I have to say, i was one of his biggest supporters. He is, without a doubt, the biggest box office draw for the UFC. When he was doing well, i always had my doubts about his real ability. He had some impressive wins, most of which were fast KO's, so i never really knew how he would do in a real fight.
First of all, i think his decision to fight Diaz was a terrible one. He is not a 170lbs fighter and Diaz was a fighter on a 19-10 record at the time of the fight (ie, not exactly an Elite fighter). He ended up losing in a submission. The second fight was a fluke, Conor won, but it was a controversial decision. So he spent time fighting a fighter, that he should not have, in a division he never planned to participate in. Conor was best at 145.155 was an option, but 170lbs is not his weight class.
Besides this, it also put the whole divisions (155 and 145) on hold because he was the title holder at the time these 2 fights were taking place. Think about it, when was the last time a fighter, who held 2 titles, competed in a totally different weight in a random fight against a mid tier fighter? No disrespect to Diaz, but, he did not deserve to be fighting the biggest draw in UFC history. Do not get me wrong, those 2 fights were entertaining, but from the point of view of legacy, they did nothing for Conor.
Then came the fight with Mayweather. I for one, hated this idea. It possibly was good for the UFC and for Conor's pocket, but i am a MMA fan. I want to see how far Conor can get. In the end he lost, which was predictable. He never really had a chance against one of the best boxers in history and after that, Conor lost any real interest in MMA. Frankly speaking, i do not blame the guy. The dude grew up poor and here he is, with tens of millions. Following that, he was stripped of his title (which was the only thing to do, he was not defending the titles for months).
Then we had the bus incident, court cases, the beat down by Khabib. There were lots of other cases out of the cage, such as him cheating on his wife and more recently him striking an old man in a pub.
In my opinion, he never could challenge the legacy of fighters like GSP, Silva, Jones, Fedor, but he could at least be a top 5 level fighter if his head was screwed on right. Now he is 31y old with a respectable 21-4 record. He was on a 21-3 record as a 28y old. Basically the dude pissed away his prime.
I still love the dude, just wished he would do more. Obviously, i am sure he does not give a shit what his fans think, he will end up the richest fighter to ever compete in MMA, so i guess, mission accomplished.
ADDED LATER:What some of his supporters said about him recently