Fine but nobody in history comes close to that streak. Fischer does not get full credit for his chess skill because he was a nut.
If you look at the forums here, it looks like the opposite : Fischer is not seen as nuts because of his tremendous chess skills.
I see then as separate questions.
Everyone agrees Fisher was a great chess player.
He was always at least eccentric and difficult and after he left chess went completely round the twist.
He held some very anti-semitic views, like real Nazi stuff, he publicised on his web site. This is probably even more loony from someone with some Jewish ancestors like Fisher.
Carlsen extremely over rated.
Carlsen has been "extremely overrated" since the first time I heard of him. He would never reach top 100, beat a top player, reach top 10, win a top tournament, reach #1 on the rating list, stay #1, pass 70 points down to #2, qualify for a title match, win a title match, keep the title, etc. But people never give up about how overrated he is :-)
I can't help but wonder which results he should have scored not to be overrated. In his last ten tournaments he has won seven and finished second in the remaining three, and if he beats Anand again he will win the Chess Oscar for best player six consecutive years, that's a first, and not bad for a player who turned 23 just a few months ago. At least not compared to all the not overrated players out there.