Why learn a martial art?

[Otaku]

Prefacing this with my usual thing - I know mostly 3e. I think, as usual I failed to make this clear enough when writing (that I am using 3e for reference), and for that I apologize.

Originally Posted by Ulzgoroth

This is not the case. You can have brawling, boxing, karate, wrestling, judo, and sumo skills without having any style.

If your setting is not using the rules for styles... correct. That would be a setting where you wouldn't be able to purchase Style Familiarity to begin with... unless you like wasting points and your GM is okay with that.

Otherwise there is no such thing as a "generic" style... or perhaps there is only the "generic" version of the style. Style Familiarity is for a major branch of Martial Arts; don't micromanage it. Some official Styles from GURPS Martial Arts (well, at least 3e) are variations of the same underlying form... but usually it took something significant for the subdivision.

Martial Arts 3e has French Fencing and Italian Rapier Fencing; just looking at the Primary Skills of those two styles, you can see why they were split. The former uses Fencing (Smallsword) and Fencing Art while the Primary Skills of the latter are Cloak, Fencing (Rapier), and Main-Gauche. They have overlapping but different Secondary and Optional Skills, as well as different Maneuvers [Techniques].

So I find this idea of throwing a "generic Karate punch" self-refuting; if the strike is different enough from your own style as to not count as your own style... then it is another style.

Originally Posted by Ulzgoroth

What this represents is fairly obvious...someone who's picked up the skill without studying any school (or even 'school') and thus whatever quirks their idiosyncratic style might have, nobody is going to be familiar with them.

Again, this is self-refuting. If the character didn't invent it the style his/her/itself, they learned it from someone (even indirectly, such as from written instructions). If the difference between learning Karate from studying it through text books and from learning it at an actual dojo is pronounced enough to count as a different "Style"... then it is a different style. If they are truly self-taught (everything they know about fighting comes from personal invention)... they may have their own unique style, but it isn't "generic".

If you want someone to perform a technique so that it doesn't resemble their actual style, I would consider allowing it but at a penalty depending on the circumstances.

Originally Posted by Ulzgoroth

It's slightly perverse that that character could then learn a style and in the process become predictable to all practitioners. I wonder if an additional perk would be enough to buy away the 'recognizable style' penalty.

You'll need to explain why it is "slightly perverse". Again I think you're treating personal style with martial arts style.