IMO Latin rap (which had some bright moments in the early and mid 90s - Cypress Hill, LSOB, Frost, Fat Joe, Funky Aztecs, N2Deep and others) just went the same way as rap in general - excessive use of gangsta cliches and shift of focus from music to image
That's why you see 1500 sureno rappers with shaved heads and shades rapping off beat (yes, they do) over some cheap beats (yes, you can't deny that) sounding all the same (with some rare exceptions)
Same with nortenos and every other latin rapper
Black gangsta rappers still get airplay and sell (well, used to sell) lots of units because of certain reasons having lots to do with the way white America perceives black men
A latin gangster isn't even a fraction as interesting as a black one because most, if not all of them are some bald overweight dudes (no disrespect) and that's not a marketable image
no 12-year girl will put a poster of Sir Dyno on her wall when the picture of 50 Cent's with his shirt off is readily available...
In the end you get lots of rappers making music for a small dedicated audience, people who will buy everything they drop just because it is norte/sur - which in turn leads to the off beat rapping, cliched topics, weak beats, 6 albums an year per artist being the norm, and all other problems plaguing the scene
it's not latin rap itself, it's the state of rap music in general that's the problem
just my 2 cents