>>9046297McFarlane gets hate because they made a couple of Japanese properties and that really riles up the weeaboos.
In general, the weeaboos are incredibly insecure that they'll even attack other Japanese brands. The first brand wars on /toy/ was between Figma and Revoltech, fighting over the Evangelion girls. Now that Revoltech has become a niche line and more newfags have come into the board, that brandwar has been mostly forgotten, but many more have taken its place (Mafex vs Figuarts, Figuarts vs Figma).
Whereas western brands are pretty much cool with one another, where Mezco interacts with Diamond and Hasbro, NECA with McFarlane, and even non-Japanese Asian lines like Storm Collectibles interacts with McFarlane/Mattel. See also 1:18 where different lines across the world share a single General.