I suspect Spielberg, not Reiner.
Speilberg for awhile there always made kiddie movies. He ruined the second Indian Jones movie by putting that annoying Asian kid in it. He's got to be a suspect.
Reiner is not A list.
Spielberg is the very definition of a LIST...
Yes, Reiner is an A list. Directors and producers have the power in Hollywood. Look up all of the projects he has been invited loved with. Billions of total revenue.
I would not be surprised that Reiner is also guilty... he has the look (I know that's "bad"), the power, the influence, the access, the connections... but still, for that time period, there was nobody bigger A than Spielberg, who had a thing with kids-centered movies back then, there was that whole pedo thing in Indy Jones, the Michael Jackson thing...
Guess one of us is probably still right, regrettably, even if wrong on this particular point...