No you should just not do any research of your own and say "It's the Bills, we're doomed!"
No one knows how this hire will work out, but they guy clearly has a good resume (player, 25+ years of coaching), worked under a respected coach in Kubiak (who called Dennison "the second voice in his head), has respect within NFL coaching circles, had been mentioned in Head Coaching searches over the years and has held the OC position multiple times for multiple teams.
Let's give him a chance before saying flat out "he never called plays and didn't coordinate the passing game, we're doomed!" (unless you were in the room with him over the years, then please, enlighten us).