Because it seems that he lost those rounds.
McGregor was TKO'd, so, the win of a fight goes to he who prevails at the end, not to earlier perceptions in the battle as it unfolds.
Yes, tired out. Mayweather didn't land much of anything until after McGregor started losing steam. That's just a fact.
So, I'm saying, if McGregor was the better fighter he would
not have lost steam. Endurance is an essential aspect to boxing, so is conserving energy, not early perceptions, kind of like knowing you have a 30 mile hump in the infantry that will include marching up and down hills. You might look good running the first several miles with the pack on your back, but its possible the turtles behind you keeping at good stride might eventually march past you.
And Mayweather fought like the US military. The Marine Corps infantry likes to attack its enemies when they are not only tired but hopefully undressed, in bed asleep, and no weapon on them. That's why we prefer to attack, to assault, at zero dark thirty hours, early in the morning before the sun comes up.
...He also kept being a coward and turning his back to McGregor whenever he felt threatened. That's also a fact.
If he was a coward he never would have gotten in the ring with McGregor. Neither of them can be justly accused of being cowards. And its not even just about this one fight for that matter. Both have a series of fights before this under their belts. Floyd has been
boxing (not playing golf) since he was a little boy. And he earned his livelihood as an adult as a professional boxer and fought some of the best out there. He was not earning his money punching keyboards, hanging drywall, or being a career politician. He was earning his money in a physically violent job--one that often leaves former fighters "punch drunk."
Put any fight in a ring aside, just putting on the gloves and walking up to the ring puts butterflies in most men's bellies, and especially going underneath the ropes to enter the ring. That's even just in a boxing gym for sparring. Fighting as they did under huge bright lights in front on hundreds, thousands, screaming fans, TV cameras being on you... that is a whole level of fear I've never experienced and few men have. How many times has Floyd willfully put himself through that gauntlet? Many.
Arturo Gatti was famous for taking far worse beatings than McGregor did and coming back strong. This guy would get beaten up bad like a Rocky movie, knocked down to the mat, and come up fighting even
harder. And you're complaining about McGregor getting "tired." Yeah, it was obvious he was tired. Made especially so from Floyd's hits (including the body hits in the early rounds). McGregor didn't have the conditioning to endure through a 12 round boxing fight.
Lastly... Teddy Atlas knows far more about boxing than I do and sees and understands what goes on in a ring between two opponent to a way greater extent than I do. He addresses this issue of Mayweather's back being turned and so does a former professional MMA fighter (I believe he's a former MMA fighter).
One can fast-foward to approximately the 11:40 mark of the video. That is when Teddy addresses the back turns and states McGregor was turning Mayweather (although, sometimes I think he had stepped towards the back side of Mayweather).
