Hmm, I hated Fuuko and Ryou, didn't care for Kotomi or Nagisa or <insert other side characters no one cares about here>, I liked Tomoyo, Kyou da best girl, Nagisa's parents were the best characters, I disliked half the routes in Clannad and liked the other half, I liked After Story and think it did some things very very well, I still disliked Nagisa throughout the whole thing because she's a bad character, I liked Kyou coming back, I hated Fuuko coming back, and the ending is an abomination that very nearly ruined the entire thing for me and actually might have had it been the anime I saw rather than the VN.
You know, I can't tell if this post disproves your assertion or merely reinforces it. I guess overall I liked it, but more in a "the good half outweighed the bad half mostly" way.
Now Corvo needs to watch Angel Beats to appreciate TRUE suffering.