Well technically the playtest said "this is what people not playing something else wanted". Given the sales numbers at the time with pathfinder outselling 4e It's more than reasonable to say that the online posters disallusioned with 5e are probably not nearly as much of a bad example as your making it out to be. That goes double when you toss on how bad wotc is with near push polling, questionable sampling that rarely bothered to even ask critical things like if someone is answering as a gm or a player, & poll questions phrased in such a way that the result can mean anything someone wants it to say regardless of if it's a landslide either way or somewhere in between.Because the playtest said this is what people wanted. Online posters on forums really aren't a good example of the average player/DM. If it was the Champion Fighter probably wouldn't exist.
So if you define "average playr/DM [of the time]" to be "from the subset of players & GMs not playing/DMing the best selling or second most best selling ttrpg of the time for whatever reason" sure... But it's not like everyone went from playing 3.5 to playing WoW when 4e came out. Plenty tried 4e, some even liked 4e & kept with it... sales numbers show where most everyone else went. Once you start defining "average player/DM" like that your pretty much putting a spotlight on how tiny that minority slice is.