RE: AprilTTRPGMaker Day 21: How many playtests?
I will admit that occasionally the temptation to publish stuff without playtesting is pretty large (I've often released not fully playtested things with the caveat that they're still being playtested), but I wish it weren't controversial to say people should playtest.
That's not to say that you need a broad and far-reaching playtest for every game: unless you're WoTC or Paizo that's impractical, but you need to have played the game to understand whether or not it's something you can put out in good faith.
I suspect that several A-list publishers have been skimping on playtesting (or at least, at one point, were, during the end of my time as a game reviewer), and it shows when something just hasn't gotten enough time in development and playtesting.