No it's because some voobly mods are biased af (proven by many people before)
Is there any official complain about bl4ck? (with real facts, not with some random words)
it's probably just random kiddish behaviour at every level (from 1600, more common, to 2500+, less common), I had that random behaviour before (against me in some games) and I don't hive a **** about it. Because I know the other guy doesn't care who I am, he's just angry bcs of losing and shiet.
Apart from that, IMO the same level can't be applied for both and that's what chris applied:
bl4ck's "job" is playing, if he fails at it (low rate) he can't participate. If he gets A LOT of complains, he may be punished, but I guess there was not many official complains. <-- Probably some kind of chat ban should work too :P
River's "job" is speaking/casting, if he fails at it, he can't participate.