When Anderson Silva dominated Maia, it was objectively one of the most impressive dismantling's of one of the greatest specialists in MMA history. He treated a world title challenger like he wasn't even worthy of sharing the cage. Maia shuffled along the cage completely at the mercy of Silva.
A Maia who started his UFC career with 5 consecutive victories all by submission, a feat not done since Royce Gracie did it in 1994.
A fighter can have an objectively great win. But the fans, bosses, and media decide if it was awesome or a downright disgrace. Historically speaking, not many fans have even seen a fight like that before, even prime GSP wasn't controlling guys for 20+ minutes. Has there ever been a fighter in UFC history who had that much control, and yet so little fight finishing attempts? It was objectively a historically uneventful fight, one that no modern fans have ever seen before.
Merab gets a lot of crap here, but I'd argue he's never had a performance quite like that. It's not really a slight against Khamzat, it's just facts. You can't fight that way and expect adulation from the fans, it's never worked that way.