Here's how you shut up anyone who presents you with some bullshyt narrative about how well Conor legitimately did against a boxing great:
Tell them to watch the fight twice more. Once while only watching McGregor, and once while only watching Mayweather. When watching Conor, tell them to note the types of punches that Conor throws, the power on those punches, and the form on those punches as the fight progresses. Tell them to note Conor's movement, as well as how his wind holds up round-by-round. Tell them to note how everything basically falls off a cliff for Conor after round 6 or so.
When watching Mayweather, tell them to note that Conor's best shot came in the first round (the left uppercut) and Floyd walked through it to the extent that you wouldn't have noticed it if it hadn't been replayed. Tell them to note that, at times, Floyd is not only defending Conor's shots, but as times deliberately taking his punches just to show him that Conor's power isn't affecting him at all. Tell them to note that, for all of Conor's "work," Floyd looked like he had a light run before a sparring match. And tell them to note that, when Floyd decided that he'd had enough of this exhibition (because that's really what this was, not a legitimate boxing match), he just put his hands up, walked through his shots with zero fear, and just beat on him to his heart's content.
If they do not notice this, they are idiots and cannot be helped. Conor didn't do as badly as everyone thought, but let's all be honest: it went exactly as long as Floyd wanted it to.