I think if youre playing someone randomly you don't know then it can just be instinct to hit the ball back rather than try to make winning shots. If you then win comfortably you have obviously done all you need to win. If that was just pushing then I would say its more your opponent not forcing more out of you.
I would take no notice if it was me. I play plenty of pushers and moonballers and they are frustrating to play against, but I take it that its down to me to work them more.
I'd ignore comments like that if I were you.
"Tennis is just chess with balls."
Sometimes: Dunlop Biomimetic 300 - Sometimes: Prince Exo3 Graphite 93