What I'm seeing here is basically people judging these movies based on Muppet content; which characters appear, how they're used, etc...
I try to judge these movies as FILMS. And while I can't really fault someone for not liking Christmas Carol as much because how it casts and uses the Muppets, I think AS A FILM, it's worlds ahead of the later two '90s movies. The special effects are fantastic, Michael Cain is a perfect Scrooge, the soundtrack is exceptional, the funny bits are funny, the scary bits are threatening, the emotional bits are effective. Like I said, there's a reason why it gets so much love and is often cited as not only a holiday classic, but one of the very best Christmas Carol adaptions.