Why does some people (in my experience, at least) have so conflicted opinions about "Silent Hill: Retribution"?

I mean, the biggest criticism is that, in representing (SPOILERS) Silent Hill 3, Pyramid Head, that comes from SH2, is in that film. I mean, is that really the most outrageous aspect about the whole movies? They could’ve focused more on the fact that Silent Hill is truly described for the 1st time. Unless they’re puritans, of course. But their view does get more echoed. It’s like refusing to play the last four games of SH (for the matter, they’re 8, produced by Konami) because they are not canon. I mean, I just reported the mainstream opinions about the games. Another example that could be made is that when watching an anime (like Dragon Ball, Japanese animated TV series) fillers must be avoided because, by definition, the Japanese comics (manga) don’t mention the events there. I mean, what’s the big deal?