Who are the 'pretty shit' opponents that Robinson lost to? Who is Ray LaMotta? Jake LaMotta was a pretty good fighter, a guy that went out of his way to fight the best guys around.
More thugs than athletes? My gracious...those guys fought a lot because that was how you make a living, you work at your trade. That is also how you get good at something, and it shows.
For the most part, the skill level in modern boxing is horrible. Guys take turns punching- you don't see much slipping and countering, the bobbing and weaving. No class, for the most part.