Royce Gracie was asked why the newer generation of Gracies aren't as dominant in MMA anymore, and the UFC Hall-of-Famer stated that he believes it's because they have forgotten about their BJJ roots:

"Jiu-jitsu is enough. I’ve trained boxing in the past to learn the distance, trained wrestling to understand how he would take me down, but I won’t get there to fight my opponent’s game. The (new) guys (from the Gracie) family want to complement their game, like if jiu-jitsu was incomplete. I guess they forgot a little about history." "I’m going to learn boxing in six months because my opponent is good in boxing? That makes no sense."

Some fans and pundits have thought that Royce's "old school" style vs. style mentality isn't applicable in the current MMA landscape which demands fighters to be more complete and well rounded. But apparently, there are other people who consider even Royce himself to still be too divergent from their 'jiujitsu only' beliefs.

Relson Gracie tells PVT that by Renzo and Royce cross training in other disciplines, they're disrespecting Helio. The 61-year-old even went as far as saying that this has put a rift between him and his younger brother. (Translation via BJJEE):

"I think (Royce) and Renzo have forgotten Jiu-Jitsu a bit … Nowadays, you go in the gym and see them fighting Muay Thai, kicking etc. I’ll never use this in my life to fight someone. Helio Gracie would not like that, but Royce trains these things. And Royce lost to Hughes because he changed his style. If he had fought Jiu-Jitsu … I think Royce disrespected my father. I have no more communication with Royce since then. I do not talk to him anymore. It affected me a lot. He took a beating because he was fighting Muay Thai. If he had walked backwards using the stomp, he would had caught Matt Hugues. If he had done it earlier in the UFC … But he changed his coach. Put me out. He never lost with me." "Royce was the most amateur member of the family to fight in the UFC. If someone was to put in there to kick butt it would have been Rickson, me, or anyone who was more of brawler than Royce. Royce was never in a street fight as a boy. He never won a gold medal in Jiu-Jitsu. So, he was the most inexperienced fighter in the world. Royce has fingers like a pianist. But he followed Helio Gracie’s plan, and it paid off. On the day that he began to change, it was over for him"

Renzo of course has responded to similar criticism from Royce in the past, saying "We didn't forget s--t" as he spoke in detail about a much more realistic approach to training. You can check out Renzo's entire statement about 'forgetting jiujitsu' here, which I assume would be a very similar reaction to Relson's criticism as well.