RPGMemes

There's a lot to be said about how GURPS is clunky - and it is, even when you're not digging into the insane optional rules - but I think its biggest flaw, by far, was that it had very little appreciation for genre. GURPS was built on the notion that a single system could tell any story, but what that meant in practice was that a single system could tell a story with different trappings. GURPS was set dressing applied to a core system that ultimately imposes certain genre constraints on anything you tried to run with it. This is true of all systems, but GURPS tries to act like it isn't.

That's not to say that it's universally bad. A lot of the settings for it do fit well in the mold it offers. Alpha Centauri is fantastic in GURPS, and it's a wonderful system for the huge line of historical settings it offers, if you're looking for a more grounded, simulationist take. But there are also plenty that don't. Illuminati University is brilliant but has no business being a GURPS setting. That game desperately wants to be PbtA. Ditto Discworld. Star Trek makes no sense; that game probably wants to be running on something like Cortex, the relationship engine would work beautifully with Trek's tone and themes.

God help you if you actually think the WoD conversions are a good idea. And who in their right mind ever thought it was the right system for Hellboy?

No system can ever be universal, because roleplaying games are stories, not historical re-enactments. That matters.