Hi,
Just to put this "kata vs no kata" thing to bed, this may help those that think they don't train in it (from another of my posts in a different thread):
Well, kata is a Japanese term that literally means "form", or "shape". The method of training refered to as kata training is what NLP practitioners refer to as "modeling". In this method, the student repeats the same movements and actions over and over without changing them, in order to instill the basic strategies and concepts of a martial system. As a result, you could even say that BJJ uses a kata method, in that you constantly repeat the same action (a particular sweep, for example) over and over in order to be able to use it at any time. The term used would probably simply be "drill", though.
In old Japanese arts, known as koryu (old styles), kata training often refers to paired combat exercises, with a specific attack and response scenario. This is applied to unarmed and weapon schools alike, with different schools having longer or shorter kata depending on the school in question. This type of kata training exists even in more modern systems such as BJJ and Judo.
In more modern arts (such as karate, tae kwon do, various kung fu systems), the kata/form/poomse approach is far more often a long string of movements practiced solo. This is, as stated, not the only definition of "kata".
Okay, hopefully that helps...
As for whether or not there is too much "flash" in TMA systems, which is useless, I would want to break that down a bit first. To begin with, how are we defining Traditional Martial Arts? There are some (probably quite a few here, actually) who will happily clsas Tae Kwon Do, Aikido, Karate (most Japanese based systems I am refering to here...)and various other quite modern creations as TMA. Some will even give Krav Maga that title. So it's going to come down to how you define "Traditional".
Then, we need to understand what is meant by "useless". Training with a sword (Kendo, Iaido, Taiji etc) is not really immediately applicable to a real-world self defence scenario, so could be taken as "useless" if that is the criteria. By the same token, certain training drills and practices, flashy or not, are not exactly very good representations of the realities that could be faced. Again, we would refer to these as "useless".
Finally, how are we defining "flashy"? Show a boxer a high-level limb control or throw/immobilisation combination, and they could consider that quite flashy, and ask why you don't simply hit the guy? By the same token, a Judoka may consider a leaping spinning kick from Tae Kwon Do to be very flashy and impractical.
From my perspective, yes, there are some overly flashy aspects in some TMA systems which is not particularly useful in a modern assault scenario, but that is hardly anything new. And in those systems, I'm sure you will find that there is a reason for those flashy movements, which may even include simply looking impressive to score more points in a competition, or to generate awe-inspired students (wow, can't wait til I can do that!).
Earlier, someone was asked for examples of flashy movements and unrealistic training exercises. Okay, here you go:
http://www.collegehumor.com/video:1749038/context/tag:martial-arts/
This clip was taken as an advertisement for the club, but has been re-edited for humour (and schadenfreude, I feel...), but shows the flashy-style movements as well as an unrealistic training habit (the attacker launching a single attack, then just waiting for the response). Other dangerous habits I commonly see (most ofte in Karate and Tae Kwon Do schools... not trying to pick on you guys, but this type of drill is what you guys do most) are after the single attack, the defender responds with a series of strikes and kicks, and the attacker simply stands in place. There is no reaction to the effect such strikes and kicks would have, so no realistic openings are created, no realistic body shapes are presented, and the defender (unconsciously, at least) gets the message that their strikes and kicks don't move the opponent. Not flashy, but not particularly realistic either.