Wither Cordelia?

When I bore everyone praise the fourth season of Angel as my favourite and as the best written one overall (if you take the entire season, from start to finish, not just parts), I often hear the objection "yes/maybe, but I am a Cordelia fan, and what they did to her...". Now, this never fails to puzzle me, because I was a Cordelia fan, and to me, the damage was always done in season 3; 4, again, to me, was if anything a salvage operation because the Jasmine retcon explained Cordelia's s3 behaviour in a way I could stomach, and turned it into the part of a Greek tragedy. However, thinking the matter through, it occured to me that the problem of the writing for Cordelia actually might predate both seasons.

( Spoilers for all seasons of both shows )