Mayweather's recent record is a questionable but I don't think you can call an overall record that has many quality names on it as being "fraudulent".
He's so good and was capable of so much more. Canelo is his best win in several years. His run at 140 was pathetic. Gatti was his signature win at 140 when Kostya Tszyu, and undefeated prime Ricky Hatton and an
up an coming bull in the form of Miguel Cotto was available. He moved to 147 and beat Zab Judah and Carlos Baldomir. WOW! Then he retired rather than face Margarito, Mosley, Cotto or Manny.
He's a fraud. Put Floyd in the 80's with Hearns, Leonard, Benitez and Duran. I won't say Hagler or Mike McCallum because Floyd wouldn't so much as look at those two if they were in the same room.
In order, he'd get destroyed by Hearns and Leonard. He'd lose to Duran and Benitez. He'd have moments against Benitez and Duran, but would still lose.
Now, if the Duran fight happened below 147? Say at 135 when Duran was primed? Floyd would get run the fuck out of the ring.
At 135, he'd also have big problems with Arguello and at 140 would be in deep against Aaron Pryor.