Why are Joe Rogan and Daniel Cormier being criticized for biased commentary at UFC 259?

Joe Rogan and Daniel Cormier are being lambasted for their commentary at UFC 259, which many fans and fighters have claimed was biased. According to several UFC competitors, Rogan and Cormier were partial towards Israel Adesanya during his light heavyweight debut against Jan Blachowicz at UFC 259.

'The Last Stylebender' suffered the first loss of his MMA career to Blachowicz in the UFC 259 headliner. The judges scored the contest unanimously in Blachowicz's favor with the scores of 49-46, 49-45, 49-45.

The MMA community, however, is not pleased with the way Joe Rogan and Daniel Cormier called the main event fight.

could have used a little less bias by the commentary team last night at #UFC259. I have the utmost respect for guys like @joerogan & @dc_mma, but last night was very evident that Adesanya was the commentary team’s favourite.. The bias made it hard to listen to, but great fights!!
— a.stuetz (@StuetzA) March 7, 2021

Loved the ufc fight yesterday, my only issue was the commentary for the main event. The bias towards Adesanya the entire fight and they made it seem like he won it comfortably. As commentators, you're supposed to be neutral.
— UtdKaashif ✨ (@utd_kaashif) March 7, 2021

Jeeeze the commentary bias for Adesanya. He’s looked great, but Jan is giving him trouble. #UFC259 #MMATwitter
— TRT Vitor (c. 2013) (@SaucyVitor) March 7, 2021

At the end of the five-round battle, Joe Rogan and Daniel Cormier appeared to disagree with two judges who scored the fight 49-45.

Which UFC fighters slammed Joe Rogan and Daniel Cormier's commentary?

After Jan Blachowicz was declared the winner of the UFC 259 main event, Marvin Vettori took to Twitter to express his displeasure with Joe Rogan and Daniel Cormier's commentary. 'The Italian Dream' said it was "unbelievable" how biased the commentators were during the main event.

Commentary is so bias is unbelievable, makes me hate this shit
— Marvin Vettori (@MarvinVettori) March 7, 2021

Vettori also noted that he "can't wait" to fight Israel Adesanya fight once again. The No.5 ranked middleweight locked horns with the middleweight champion in 2018. Vettori was able to survive all three rounds against Adesanya, but found himself on the wrong side of a split decision.

Following his big win over Jack Hermansson last year, Vettori said he would like a rematch against 'The Last Stylebender' in the future. Adesanya's win against Vettori continues to remain the only split decision victory of his MMA career.

Former UFC interim lightweight champion Justin Gaethje also seemed discontented with the supposed bias of the commentary team at UFC 259. 'The Highlight' stated Blachowicz clearly won the first two rounds of the fight, and that the commentary was "unbelievably biased."

Told you so as did every judge. The commentary was unbelievably biased tonight.
— Justin Gaethje 🇺🇸 (@Justin_Gaethje) March 7, 2021

Gaethje, the No.2 ranked UFC lightweight, is waiting for his next fight to come to fruition. The 32-year-old last fought Khabib Nurmagomedov at UFC 254 in October 2020, where he was choked out by 'The Eagle' in the second round of the fight.