You should know that Yik Yak is an amalgamation of whatever the users say around you... If it's filled with hate speech, that would be your surrounding environments fault and not Yik Yak.
Btw, I'm in Europe, so all of the comments I saw were in English, as in American English, so I'm guessing us Europeans aren't getting the best of the US. This is not data, just an observation.
Entirely off-topic, but what English variant is taught in Europe? I'm going to ask a German colleague to spell the word 'colour' I think.