I understand your analogy, but if you think about it, this analogy would only be applicable if I was a virgin. It assumes I have little or no sexual "experience" so to speak. I'm sure this is not what you are suggesting, but you have to consider that the person might have a whole lot more experience with sex than you do (don't assume things -

)
(emphasis added)
Not necessarily. There is a natural learned behavior to stick with what we have experienced works, and resist change to an unknown or unproven condition (at least unproven to that individual). However, to say that we are "set in our ways" implies that we shut ourselves off to evidence contrary to our beliefs. It is true that people usually do not switch just because someone else suggests a different way, but why would anyone change without irrefutable proof that the other way is better.
It would be an error for you to think that you are the only one here who has experience with both of these types of kicks, or that you have more experience with them. I submit that your personal experience and preferences are simply different than mine, not more knowledgeable.
OK, let's look at what you have claimed:
1.
The shin is a safer attacking tool. - - safety of the instep kick is in its correct application, and shin attacks have higher risk of counters.
2.
The shin is a more damaging tool. - - This one is not proven, and I believe incorrect.
Alright, here is issue one: "safety." In this reference, you seem to be focusing on the safety of you, the kicker, not to be injured while attacking. Here are some flaws with this logic. First, you are only comparing the "shin" to the "instep." While I might use the instep in certain applications to specific targets at the right time, my primary tools to kick the leg will be the ball (front kick or roundhouse) arch (inward stomp), and blade or heel (side kick).
Believe me, the issue of an opponent moving rather than standing still for me to kick them is not a new concept to me.

I choose my targets, timing, and power wisely so as not to "risk" accidental injury, and I control my attack so that I can stop, or change the kick if my opponent moves in a position I don't like.
This too is not a new concept, and Taekwondo uses various types of defenses as well. However, it is a very risky thing to do. Don't think for a moment that a lifelong kicker, such as myself, has not considered what to do if a "muay thai" person, or anyone else raises their leg as a "shield." This movement opens the groin, pins the weight on the opposite leg, and provides for a variety of counter moves without ever making impact with the intended "shield."
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Yes, I guess you could learn this "the hard way" :ultracool However, it is a foolish maneuver for anyone to launch an initial attack by kicking "as hard as you can." If you are concerned about safety, as you say, then remember that initial strikes are light to medium contact to distract, and temporarily disable your opponent to set them up for the power kick that they will then not be physically able to move, shield, deflect, or do anything to prevent.
Again, here you are talking about your own personal experiences which might be isolated to certain circumstances that you were in at that time. How many times have you been kicked by each type of kick? Did the instep kick strike the exact same target as the shin kick? Was the person doing the instep kick as skilled at Taekwondo type instep kicks as the person doing the shin kick (how do you know), and was the instep kick really delivered with as much potential power as it could have been? (again, how do you know).
This goes to issue 2 of your claim: "The shin is a more damaging tool."
Are there other people in Taekwondo who could possibly drop you with one single instep kick to your thigh, or knee? This is also neglecting the ball of the foot roundhouse which would do more damage than both instep or shin kick (proof??? break some boards with your shin - - with your instep - - with the ball of the foot. Which technique will break more boards?)
Going with this theory for a moment, would you contend that the inner forearm would be better than a ridge hand strike. If I were to strike the side of a person's head, by your analogy, the forearm is more solid like a bat. The hand has smaller bones. Should I swing my arm at the shoulder and strike with the sharp inner forearm rather than the surface of the fragile bones of the ridge hand. Again, break some board both ways and test the results - - or, pad up an opponent with
really thick, tripple layer,body pads and test ridge hand vs. inner forearm, and instep vs. shin to the ribs.
When it comes to potential damage, it depends on who is executing the kick, what the target is, and how the technique is performed. For power and damage, I opt for the ball of the foot roundhouse as compared to a similar motion of the shin kick, however other kicks work better to the legs, and give you more options.
When it comes to "safety," not only is this an issue for proper application, timing, and control, but there is a more important "safety" issue. If you stick your hand in the open mouth of an alligator, you might be able to pull it out before he snaps it shut. However, if you stick your arm in elbow deep, be prepared to lose your arm. Aside from the fact that you have to be physically closer to your opponent to attack with the shin (mistake - risky - unsafe!), you are inserting your leg further into a potential trap (fatal mistake - very risky - no where near safe!)
Attacking your opponent's leg with the foot has some risks, but sticking your leg in far enough to use the shin will only work if the alligator is sleeping or dead. You better believe that I have analyzed the kicking with the shin application from every angle over the past 31 years, and I would not have a problem with destroying a person who attempted such a risky move. I have counters for that type of kick that do not fail, but I won't reveal them here (momma didn't raise no fool! :ultracool )
Well, I'm glad to hear that you consider yourself an "expert" on the subject, but let me assure you, I was only joking earlier when I said that "I am just a beginner at Taekwondo." Don't be misled to think that Taekwondo is all I know. I know what boxers do, how wrestlers move, what the tactics of jujutsu (jujitsu and judo) players. I know how Karate and Kung-fu approach attacks, and I am well aware of the skills attempted by Muay Thai fighters.
Taekwondo, within itself, has methods of dealing with all of these without having to borrow their techniques simply because some good practitioners of one system have been successful at applying them to a not so good practitioner of another (This is a general observation, and not intended to refer to you or anyone else here at MT). I train to be good at what I do, then there is no penetration by techniques that Taekwondoists have ruled out as being not beneficial or safe.
Again, these are just my opinions, but they are not derived from a lack of expertise either. Thanks for sharing, though!
CM D.J. Eisenhart