It's because Val genuinely felt sorry for Bruce. He saw the story where Batgirl hit Batman so fast he didn't even realize he'd been hit until he started to bleed and just..just felt so much sympathy for this poor guy.
Have a heart man, do you go around destroying the presents of orphans on Christmas Eve? When "Santa" shows up do you tell all the little kids Santa isn't real? Then let poor Batman have this.
You see, Karate Kid is not the only one with this problem.
Let's look at Karnak, for example. Uber skill? Granted, can KO Surfer and stuff. But what MAs can he beat in h2h? Well, certainly not BP, not even on his best day...
The Mandarin has the same problem - uber striking power, chi control, karate mastery, etc. And classic Tony without his armor actually managed to fight him for a bit...
Gamora. Knows most MA styles in the galaxy. Can't deal with Bucky who doesn't even want to fight her...
Okay, but none of what you just said explained why you would feel a character who is a martial artist and doiesn't have feats on Val's level would be able to fight him.
Yep, comics can be dumb and inconsistent, but let's not pretend like Val has 2 awesome feats and everything else is crap.
I'm legitimately asking: which martial artist could defeat him..despite having no feats on his level?
Think of Karate Kid as Magneto. Magneto does all kinds of crazy shit besides just manipulating various metals..and we buy it because the comic usually tosses out some "something something magnetism" line. That is Karate Kid, just replace "magnetism" with space karate.
Thing is, Magneto has tons of battle feats against opponents of almost any type.
Spider-Man has a great powerset, but martial artists always know how to embarrass him.
Here on KMC, one ma's showings against other martial artists were always important. Always was used to help to gauge their skill level, as seen in the huge MA Hierarchy threads, for example.