I have heard it this way many times, not always.
I agree Absolutes usually are not something that one can count on in dealing with violence and human beings.
Other than chaos or change is the only constant I truly know.
I am not sure about your statements.
Some study the shanking videos out there. And they practice.
Random drunk college kid home from school, or domestic (either way) they might not have any training or experience.
As to physical disadvantage, not always the case, from what I saw when I was in the game a few decades ago.
And other than drunk college guy, most were not drunk or on drugs or at least not recognizable.
Mileage will vary I guess as it has between us.
If taken from the mindset there is always someone stronger/ faster / younger / bigger / smaller / better / ... then it is being used in the mindset that in a confrontation one will be hit. Maybe not a horrible knock out nor even a damaging blow, yet getting hit.
Yet, the multiplier for the knife requires little strength and little contact to break the skin.
So every Boxer that says when you step in the ring you will get hit is also wrong?
I agree with the absolute issue.
I agree it can affect some , yet if it truly is such an issue, then I wonder if any competition combat needs to say don't worry you might not get hit.
There are basics that can be done against the untrained and the partial trained.
There are training methods that allow for more advanced assaults to be addressed, with minimum to nil loss.
There are also little to no way to stop the sewing machine assassination. Wait, yes, it can be addressed if seen or squared off or prepared.
But, Rich what about the sucker punch, you can't stop against that either?
And it is hard to stop the random assault, unless one is on point / aware most of the time, or more often in higher threat areas / regions.
A couple of questions and then my thoughts an summary.
Do you train foam, rubber (flex), rubber (stiff), wood, metal or real dulled edge, or real (Scotch) tapped edge or under real control situations an actual real blade?
Many people will not even handle the real blade and attack you. Yet, if worked up to it they can process the thought. Even if it is dull, (risk of thrust) , or tapped (risk of thrust / paper cut type of cuts )
First, I agree with most of what you say , and I think you have fallen into the most / almost always issue as well, knowing what you mean, not how it reads. Not a bad thing, not a real issue, only pointing it out as you asked for opinions.
Next I tell people they will get hit. empty hand and with a knife. Pay attention.
For me getting to such a position can be a failure of multiple levels. Awareness, location, associates, other.
Note: I have never been in an actual knife fight. If they had a knife and I could get a knife, screw driver , or other improvised tool, it never came to confrontation as they no longer had the advantage. (See above about how I do not think it is for disadvantage, it is more to get an advantage in my experience and opinion. )
I have been up and down and rolling and being kicked and hit and returning what I can against multiple opponents and even gone through a plate glass window with an over sized for most, yet proper size for me, balisong in the back jeans pocket. As when I was up and could obtain the threat was not there to justify. When the treat was there including one them having a knife, I was too busy reacting and dealing with issues then trying to even the threat.
Yes, there is a lot of basics for stepping offline and cam-ing the thrusting hand offline, or passing / parrying. It takes time and exposure to get comfortable and to also learn timing and adjusting. Not Speed, timing.
One needs to understand control of the opponent and limiting their responses. Also counter strikes that have high response from the opponent.
So on to my Rules for everything.
Rule 1) Avoidance
Rule 2) See Rule #1
It is simple and many will scoff it off.
Avoid the break down in the bad part of town, drive around.
Low on gas, treat half a tank of gas as empty and then always able to have the fuel to go around.
Pay attention to the area, and take precautions.
Park under lights and easy access from entrance exit of buildings.
Avoid hanging with that one guy that is always loud and wants to test themselves, knowing they have "Friends" to cash the checks the write. And it you still go out explain to them that you will not come to their aid of the do get into trouble. And make sure everyone hears. it. One would be surprise how many more also are tired of the shenanigans.
And if actions happens, let the opponents know that he is on his own, as long as they keep it one on one and stop when he can't move any more.
The opponents hear this, and they begin to think if you would do this with people you are out with what would you do to them.
It also re-enforces everyone around you that they are on their own. And you tell the others to stay out as you will not help them for helping the jerk.
Many many more instances.
The common theme is avoiding something. Including getting into the confrontation or going to locations that are more likely to have them. It avoids engaging, until you no longer can avoid it. When types like yourself (OP) show up and start asking questions, and you explain you left and they followed, and you tried telling them you were gone, and they still choose to engage. It is the truth.
That being said, still train hard, and be prepared for whatever level threat level ones to be.
Empty hand, blunt / impact , edged (short / long ) , flexible , multiple opponents, ... competition only .
As Clint once said in a movie, A man must know is limitations. This is true, and also their happiness. If training something doesn't make someone happy or feel better than before they are very likely to not continue.
So no discouragement meant to anyone at all here.
Please go train in the art / style you want and to the level you feel comfortable.
Peace