I think your criticisms are all valid, but I still loved it.

A lot of sci-fi is plot driven, characters are just vectors for the ideas, and I found the big ideas in The Dark Forest really interesting. I'd never thought to critically about the Sagan/space optimist "people in bear suits" view of alien contact before reading the book (in spite of seeing plenty of space horror movies). And for all its faults, it maintained a tension and mystery that kept me interested to the end.

I also had trouble keeping names and even genders straight, the only character I had a connection to was Da Shi (the hard boiled cop).