Personally I think this just shows how bad grammar is across the board. I think the problem is somewhat exacerbated in the jump up scene, but that's delving into stereotypes that will cause shit storms.
I'm fairly sure a lot of it is to fit with the slang and words that are used within the genre. The post I saw the other day about everyone in the drum & bass scene calling each other 'Sir' is a good example of this. Though clearly saying "lizten to mi sik jump up mix PUREE BANGAS" might not quite have the desired effect outside of somewhat niche circles..
I've got a lot of time for jump up but it's a pisstake when I'm trying to read the info on a Facebook event page. I can't even figure out who's on the bill, where it's at or where to buy tixs because it's usally filled with unnecessary caps and lowercase b2b ★★★★