The 'putdown' that Pops was 'just an entertainer' was started by the so-called 'angry' progressive/noise makers from the NYC Jazz crowd.
Probably brought on because of the world-wide adoration that Pops enjoyed, compare to the almost total anonymity, outside NYC, 'enjoyed' by the angry young men.
He was also accused of clowning for 'the man'. Horrors!!!!! That means Pops was making too much money and appearing In too many Hollywood movies.
Somewhat similar to the talk surrounding Wynton today. I am not comparing Wynton to Pops!
Cheers