Politics aside, I can see adding Mike Pondsmith, Eric Wujcik, and John Wick to that list as creative and influential people for me in the RPG hobby.
The people who've been most influential to me are:
Gary Gygax, David "Zeb" Cook, Frank Mentzer (TSR)
Steve Jackson (SJG)
Greg Gorden (Mayfair)
Greg Costikyan (West End Games)
Mike Pondsmith (R Talsorian)
Jonathan Tweet, Mark Rein-Hagen (Lion Rampant/WW)
Kevin Sembieda and Eric Wujcik (Palladium)
Jordan Weisman (FASA, Heroclix)
I'd add the GDW crew to that list for myself: Marc Miller et. al.
I'm surprised that Dave Arneson isn't on any of the lists proffered so far.
Arneson for me personally isn't on the list, because while I'm confident his design elements definitely impacted me somewhere, it's such a muddled mess of trying to define where he and Gygax matter most, it simply gets rolled together under "Gygax".
Frankly, I only point to Gygax simply because he's the source. I couldn't extricate his design principles from anything I engage with in the hobby even though I haven't played D&D, specifically, in years. But I will never disavow its impact on me.
The others in that list and in my own, have more direct impact on me both as a GM and when I'm doing my own design work. Jeff Grubb, Zeb Cook and Pondsmith in particular, have been great influences.
"Celebrities" in D&D are laughable at best to me. Great, they found a way to make a dollar off of those I think of as casual fans that have bought into the marketing of D&D as a lifestyle. I'm not one of those people (and if you derive enjoyment from it - great, don't expect me to give a crap). I've gotten precisely zero-value from any modern RPG Celebrities at my table - and that's where it counts.