Actually, I think it's quite the opposite - I think Nick's wins are underrated.
Look at a guy like Paul Daley. He's not exactly top tier, but that's not because of his striking. It's because all of his losses come from people wrestle-fucking him and being too scared to stand with him. Nick will fight someone at their strength and could've taken the easy way out. He did it against Lawler when Lawler was on a tear as an up and coming KO artist and Nick was just a BJJ guy. Same with the boxer Noons. He gogoplatad Gomi, etc.
Ya, he hasn't won in 5-6 years, but he was suspended (which was controversial), arguably beat Condit, and loss to the GOAT WW, and the GOAT MW - no shame in that. How many people have even beaten the GOATs?
As a Diaz fan, I understand the frustration with him turning down fights and getting busted, but the guy has been fighting for almost 20 years and actually comes to fight in all of his fights. He takes training very seriously and has never really had an off-season. I don't blame him for getting tired of being punched in the face.