Agreed.
But it's pretty hard to think of a non-vocal orchestrated version of, say, the Beatles, that isn't substantially worse than the Beatles.
I am really not opposed to the orchestration of pop music at all, but in the commercial context of American popular music circa 1968, orchestration is typically a portent of doom.
Plenty of people dislike the concept of orchestration for the pre-rock era too. Sweet dance bands, Jackie Gleason, etc. etc.
But it seems to me that stuff was often fine, and that the orchestrations and arrangements were as apt to increase the quality of the material as otherwise.
I think that disappears once popular music hits the rock/soul/funk era. Orchestration tends to remove the perceived spontenaity and energy that is what makes those genres work, so you'd have to be very careful or inspired to make orchestrated pop come off as something other than watered down in those contexts.