Because you probably rarely follow pro boxing. There are enough fights in boxing, when an equal opponent on paper flies to the knockout, that's why he is boxing and for this he is loved. Conor was not equal on paper, but he showed himself very well: he took three rounds, caught the Mayweather on counterattacks, did not lose due to technique, but lost due to fatigue. Floyd used all possible chances: he attacked until the moment when the referee said "boxing", used his elbows, specially turned his back and made Conor wear Everlast anti-knockout gloves when he saw what McGregor did with the ex-world boxing champion before their fight in gloved grant. This is one of the coolest fights in the history of boxing: the sold broadcasts and the hype afterwards tell us vividly. I was ashamed to look at Pacquiao and Canelo when they fought with Mayweather. Multiple world champions shamefully stood and let the Floyd do absolutely everything.
Because this is more of a show than a fight.
On the one hand, we have the greatest boxer of our day, who has never lost, and who needs beautiful statistics. On the other, a dude from a related but different sport. It is as if the Pittsburgh Penguins were playing football with Real Madrid. It is possible to attract people, but there will be no sports intrigue. Therefore, in the fight between Floyd and Connor, it was more or less clear that Mayweather would achieve his victory. The whole question was how long it would take. Connor lasted ten rounds, although he should have fallen in the ninth, when he ran out of strength.
Why were you ashamed? Probably because in this case, the show was completely hampered by sports. On the other hand, if you were ashamed to watch it, then why did you wake up at 6 am on Sunday.