Wrong. Palmer is way closer than Gadd whose basic nature is totally different from Rich´s, more relaxed and laid back. And for pure technical ability ? The best alive Calaiuta ? Wrong again. Not even close. Your perspective and experience seems surprisingly limited. You can´t even imagine that exist today equal or even better, with "pure technical ability" (what a boring expression) drummers than he. The best are beyond "technical ability", have always been. They also produce music, improvise that is. Like Palmer even today, but not so much w/ ELP as his drum solo was merely a part of the show and so usually went the same path. ELP was a show alongside symphonic rock music. In the 70´ they were spectacular, terrific live act, a trio that sounded like an orchestra.
And people loved them, that´s why those boring critics hated them. Oh, I remember it vividly, they hated ALL the best bands but we kids laughed at those booooring old farts and bought just THE records they dissed. Well, some idiots actually tried to slag acts like Uriah Heep not to mention Yes and ELP. The best of them all. LOL. Great times : )
Of course, things tend to change. In the 80´s to preplace Palmer with Powell made ELP sound like dull hard rock. And yes indeed, ELP did get boring. But there wasn´t master Palmer anymore, was there. Palmer is exactly 1/3 of that makes it symphonic (rock) music. In music some people are irreplaceable, quite literally.
I listened to that video clip above and found nothing to be excited about, same quite dull thing like near all "technical" drum solos are. Obviously haven´t bothered listen to people like Simon Phillips who can swing and scuffle and play everything and virtually with everybody, from heavy acid blues Jack Bruce to "complex" A(dult)OR/pseudo prog Toto (never cared for them but OK whilst washing the car), with high technical standard, still going strong.
Not to mention certain musicians from totally different, very old musical cultures.
