Why does China make so many "Marxist-Leninists" go crazy?

It's like China is just that one country (aside from the Khmer Rouge) that every ML (aside from Dengists like us) agrees to hate on.

Fellow Traveler and leftypol uploaded videos criticizing them, the Shining Path hung up literal dogs to protest them, Maoists go all insane saying that it's some red fash social-imperialist nation because (insert nato propaganda here). And Hoxhaists claim that China was never socialist and that the only socialist nation ever was USSR before Khrushchev and almighty holy Albania.

What is it that makes China so controversial even among MLs? I get that it's not perfect and every AES state has their Ls, but jesus.