What is the difference between a “good” martial arts movie and a “bad” one?
Pls move to Café Society. Self reported.
The best reference is David Carradine in the pilot movie for Kung Fu. Not much fighting, poorly choreographed fights, awkward-looking actors. It has some interesting elements, but the martial arts were just horrible.
Check out Jackie Chan - How to Do Action Comedy. It’s 10 minutes and concisely shows why Jackie Chan’s Hong Kong Kung Fu films are so great.
TLDW: Practice practice practice. Do as many takes it requires. Show the action and don’t muddle it up in editing.
Starring Bruce Lee or Jackie Chan. Bonus points for John Saxon.
To me, a major element is how much plausible jeopardy the lead actor is in. If he mows down henchman after henchman and none of them land a punch, a slap, or even a mild shove… if the hero looks bored while defending himself, then I’ll be bored while watching.
Ref: every Steven Seagal movie, many Bruce Lee movies, no Jackie Chan movies.
And super bonus points for Jim Kelly 
Even though the OP didn’t ask for actual movies, I’m going to toss in Kill Bill Vol 1, just for good measure.
There’s a ton of cheesy low budget kung fu movies because there are a ton of cheesy low budget anything movies and well, they make money.
As for reasonably good ones, I like Forbidden Kingdom. Jackie Chan and Jet Li.
The Ip Man movies are fairly good, especially the first.
The thing about Jackie Chan movies is that they fail to take themselves too seriously. Nothing improves a kung fu movie like adequate comic relief, or at least some good absurdity. One commonly known as Kung Fu Hustle does a pretty good job being a good mix of dark and silly.
The lion’s share of chop-socky movies are comedy gold. The martial arts is adequate, in that it does take a lot of skill and training to not take someone’s head off in a fight scene. But it’s the level of hokiness that makes me laugh.
For example, I still laugh every time I watch the Japanese Crab Style. Cracks me right up!
Just like any other movie: directing, writing, acting, all that boring stuff. A bit more of an emphasis on choreography, but that’s about it.
Yeah, that is one aspect of Steven Seagal movies that always irked me. He never seemed to be in much danger at all, no matter how many opponents he was fighting. Often, the final solo confrontation with the main villain was just a tad better in that respect, and would go on for a ludicrous amount of time, considering that Seagal had just easily beaten about ten or so of the villain’s goons a few minutes before. But still, you never felt that Steven was ever really challenged…
The tennis pro? I raise you one body-builder. Bolo Yeung!
The Ong-Bak movies had terrific fights but I love the Shaw Brothers movies I watched growing up.