I found it hard to read the rest of your post after this. While I think it is indeed a common failing to go too far with the "believe in yourself" mindset, it does actually have real, practical use in moderation, and it seems nuts to "hate" people for it.
However I think it is fairly appropriate to 'hate' the people who preach it. It has a sinister ideological component of advocating individualism above all else, mostly to justify lack of taking responsibility for the collective good, or categorically blaming individuals for their situation. It also has fuelled a gigantic self-help industrial complex that's fairly effective at parting desperate people from their money.
To me this advice is a net negative. Of course you should believe in yourself, but that's just the baseline.
It becomes just another way to say “you failed because you’re lazy and didn’t try hard enough”.