It’s largely just the damaged ego of a weak man speaking.
There was a time when Conor was legitimately considered (incorrectly) as one of the baddest individuals in combat sport. Between Diaz, Mayweather, Khabib and Dustin, we know that it was always a largely undeserved reputation, but it’s a reputation he built his career on.
Virtually all professional fighters are ‘tough’ individuals, but there’s definitely different degrees of toughness, and Conor is on the lower end of that scale. If you look at his opponents who have beaten him, they all demonstrate toughness in certain areas (unsure about Dustin tbh - someone who knows his career better than I do will know).
Diaz - very “in your face” toughness. Willing to take a beating and still grind out the win.
Mayweather - more subtle form of toughness largely due to how good he is. His toughness is his willingness to go further, to dedicate more, to do so much in the gym that what he does in the ring is relatively easy. And do that for decades. Losing is not an option.
Khabib - tough cultural upbringing, strong martial tradition, and a genuine belief that getting to where he did was his right. His destiny.
I don’t think Conor really has any of these aspects of toughness to call upon. He’ll push aggressively for the first round or two, but if you’re still there his balls will shrink, quickly. I think he knows that as well, and it eats him up a bit.
Truthfully, his career has been a carefully orchestrated ‘smash and grab’ that has made a lot of people a lot of money. For all his mental faults, he never really had the skillset to stay at the top for very long. Hell, without some choice matchmaking I’m not sure he would’ve even had the skillset to get to the top in all honesty.