I don't know how anyone who even had a passing interest in anime couldn't have seen through his fake anime persona, it was so obviously bullshit from the outset. The only anime he could list were shows from the 90's, his childhood, which he probably hadn't seen in 3 decades, and recent degenerate trash like redo of healer which was a by all metrics a "normie filter" that appealed to Nick's coomer mindset but was still tame compared to most echi/hentai.
I think that anime fans did know that he was full of shit but gave him a pass despite that because he was fighting the good fight on behalf of Vic Lasagna, now that Nick has turned his back on the weeb wars and turned out to be a degenerate junkie who starves his children people are more willing to call him out.