No movie is just automatically decent simply because it features a certain character or characters. That makes no sense at all - it's really the script that matters. The first movie has a coherent plot that's not entirely out of left field and convoluted like the following movies. At its core, it's about 'regular' people encountering a situation that hasn't been encountered before. They're skilled, but not at a superhuman level which I certainly appreciate because... I despise superhuman characters lol.It's funny how most fans think that the first RE movie is the best and yet the first one actually doesn't have any RE character at all.
I see it as similar to Outbreak in being a 'side story' - few fans rejected Outbreak because it didn't have the main characters. Obviously I would have preferred if they had used game characters, but they didn't.