WIY, I have watched his videos and I stand by my point. Some people have become so used to just accepting that any time someone says “Oi, gevald, it’s chukas hagoyim” it becomes assur d’oraysah. His videos are a perfect example of what I said when I compared it to sushi. On his last one, people were kvetching because there was a woman in it for about two seconds, who was dressed completely tznius.
2Cents: I don’t know where the issur is to sing in front of mixed dancing audiences, if it’s even true that it something that he “does”. He gets paid to sing, he sings. You might have a point if he advertised himself as a singer for mixed audiences. But if he’s a wedding singer and he turns up at a wedding, and sometime during the second dance, the mechitza starts to sag, that doesn’t make him a bad guy or “a lunatic”.