The writers made him the whining, mush-for-character wimp. It was a planned choice to make him so hated.
Perhaps it was to make his mother (mostly ugh) less hated. She played the pompous, know-it-all I detested most of the time.
There was a stauch, pervasive, consistent feminist thread throughout the series. Wesley was the sacrificial lamb to that agenda.
Not surprising they made the young, smart, straight white male the goat. Made the stereotype appear absurd...as planned. Typical of Hollywood.
Jury's out on the "straight" adjective...