Why are so many people against Conor McGregor fighting Floyd Mayweather?

Veteran boxing promoter Bob Arum has called the Floyd Mayweather Jr.-Conor McGregor boxing match a “one-off” that will send an embarrassed (and rich) McGregor back to the UFC.

McGregor’s former opponent Jose Aldo says the fight’s “a joke.” And some boxing reporters are so bothered by the Aug. 26 event at T-Mobile Arena in Las Vegas, they’re refusing to write about it.

Lighten up, people.

Mayweather, 40, was nearly a full two years into retirement when this massive global event summoned him, an opportunity to cash in perhaps beyond the estimated $240 million he earned two years ago for fighting Manny Pacquiao.

McGregor, 29, has masterfully fulfilled his words in rising to UFC champion. He avenged his first UFC loss by beating Nate Diaz nearly a year ago and became the organization’s first simultaneous two-division champion in November.

“I’m scheduling opponents with belts and I’m telling them what I’m going to do to them, and how I’m going to do it, and then I’m doing it,” McGregor said. “The train just kind of rolls with it and picks up steam … I don’t know how many times I’ve shocked the world. … Wow, wow, wow, shock, shock, shock, then on to the next one. And I’m going to shock it once again.”

Yes, he’s a 6-1 betting underdog in Nevada sports books and likely will be picked apart by the fast, elusive Mayweather, but why the consternation about a talented, charismatic champion wanting to pursue his ultimate challenge as a stand-up fighter, selling it in entertaining form throughout?

In UFC circles, McGregor’s innovative verbal skills brought great skepticism about his ability to defeat Aldo, who was unbeaten for 10 years before absorbing a knockout punch that ended their December 2015 fight in a record 13 seconds.

“This one is supposedly the big one. Wait until you see how he falls and you all write him off after this … he becomes like Aldo. Aldo was him at one stage,” McGregor said. “Just another day for me, something I’m used to seeing.

“I’m used to the way that people react to me coming into a fight. I don’t know how many times they’ve labeled me a joke -- ‘He’s a joker. Look at the way he’s moving, he hits … he doesn’t stand a chance.’ And then the poor guy facing me has to deal with it and he’s unconscious, and then on to the next. More questions. More belts. And this will just continue until I call it a day.”

Leonard Ellerbe, the CEO of Mayweather Promotions, has heard the ridicule toward Mayweather-McGregor from those in the know, and he even took one critic to task with cameras rolling at one of the four press tour stops that drew more than 10,000 fans in New York.

“That’s the reason that our sport isn’t where football, basketball [are] … it’s because we stay in our own little box,” Ellerbe said. “You tell me, what is wrong with these two guys fighting? If you don’t want to watch it, don’t buy it. Simple as that.”

Of course it seems absurd that Mayweather, at 40, will have aged so badly in his time away that he will be caught by heavy McGregor punches.

This fight is more about the spectacle of bringing these two personalities together in one ring, pitting boxing’s best against UFC’s best and seeing what happens.

Will Mayweather finally feel emboldened enough against his 0-0 opponent to deliver an action fight to close his spectacular career at 50-0?

What will the creative, power-punching McGregor do to provide the entertainment he’s known for?

Purists have umpteen other fights to systematically analyze and debate, including two immediately on the horizon: the super-flyweight tripleheader at StubHub Center on Sept. 9 and the Canelo Alvarez-Gennady Golovkin middleweight title fight Sept. 16.

“You can’t be mad and be going out there like some media members and promoters, [saying] this is why you shouldn’t buy the fight and this and that … mind your own … business, do your job, cover the sport,” Ellerbe said. “We know what this is about. One thing is for sure, you are not going to stop this event.”

That’s a critical point. Unlike the deserved public disdain pointed at the lackluster Mayweather-Pacquiao bout, after Ellerbe and Mayweather charged fans $100 for the pay-per-view, this is the ultimate buyer-beware event.

Yet, with Ellerbe and UFC President Dana White saying more than $60 million in tickets have been sold – the Mayweather-Pacquiao record gate was $72 million – the money is flowing in.

“We didn’t ask for this. Social media was on fire because of these two guys going at it,” Ellerbe said. “The fans demanded this event and they’re going to get it.”

lance.pugmire@latimes.com

Twitter: @latimespugmire

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