One person taking exception to the disapproval is Berto himself.
In an interview with BoxingScene.com's Radio Rahim, Berto attempted to make a case for himself as a deserving opponent for the unbeaten champion:
I was probably a little surprised that [the criticism] came like it came. Everybody knows that I always show up and I always fight my ass off. I've given my whole life to this sport and to these people. At the end of the day, yeah the money is good but I got into this game as a fan and wanting to go and perform for the people. Then you have guys like Floyd who comes in, and [takes the approach of 'I don't care] whether it's boring or not - as long as I get my check.' That ain't never been me and everybody knows that and everybody sees that in my fights. That's why I'm surprised with a lot of the criticism.
When this fight was announced, the reception was almost universally lukewarm, and that's probably being generous. ESPN's Dan Rafael argued a few different challengers presented more appealing matchups for Mayweather:
First Take's Skip Bayless is also among the many dissatisfied fans:
During Thursday's press conference, Mayweather attempted to sell the public on why this will be an entertaining fight (via Sky Sports News):
Berto's record makes for slightly less impressive reading than Mayweather's endorsement. He's 3-3 in his last six bouts, and one of those defeats came to Robert Guerrero in 2012. Guerrero—you may remember—was thoroughly outclassed in Mayweather's return bout in May 2013.
According to Odds Shark, Mayweather opened as anywhere from a 30-1 to 100-1 favorite in Las Vegas.
On paper, he owns the edge in just about every category pertaining to the sport—defense, stamina, technique, agility, speed, etc. Between that and Mayweather's tedious in-ring style, next September's pay-per-view isn't exactly shaping up to be an all-time classic.
While you can understand why Berto would take the criticism around the fight personally, the objections of fans and writers aren't without merit. And no amount of pre-fight hype will change that.
The best way Berto could silence the doubters is handing Mayweather the first professional loss of his career next month.