there are differences in approach and scene divisions, of course. but they aren't fixed - there are points of convergence and interesting overlaps. your way of looking at things can't account for champion and terror danjah playing joe tunes, or ossie releasing on lightworks, or funkystepz on hyperdub, or trim mcing over becoming real and dro carey, or mala working with james blake, or petchy and his crew dancing to a joy orbison set at doldrums, or marcus nasty playing ramadanman and mosca tunes
reynolds makes room for stuff like that right? but you lot don't seem to be
of course there's going to be overlap, with the internet there's bound to be. but those overlaps are rarely crucial to anything really, they're just curiosities that make you go "huh, that's neat". and tbh "claptrap" and "square one" both stand out in a bad way when played by champion/marcus nasty or whoever. they make those sets less interesting.
like pilhead said, rudeness/street vibe is central here.
then occasionally you get "bloggy" producers like jam city who are able to capture the spirit of (in his case) grime/african house really well, but don't count on it.