It is. Clutch numbers are not repeatable, and do not vary with hitter quality. Invariably when an announcer says "this is a guy you'd want up in a big spot" he is also a guy you'd want up in the other spots too. In other words, a good player. Given how difficult it is to make the bigs among all the people who aspire to play baseball - people without the ability to perform under pressure never sniff the show. For instance, David Ortiz is ascribed to be a great clutch performer, but he was total doggy poop in the ALCS, but since the tree fell where no baseball writer was looking, there was no narrative about it.
For fans, there are clutch moments for sure. But the idea that there is something about RISP that fundamentally change hitters is just not borne out in any sort of data. Put simply, in basketball for example, you always heard the idea "I'd love to have Larry Bird taking that last shot". Of course you do, because you'd want Larry Bird (of 1986 vintage, not Indiana Pacers GM one) to take EVERY SHOT.