1. De La Hoya was much, much bigger and still actually an elite fighter. That's why he had success. A Prime De La Hoya would of had more success because he would of been able to compete with Floyd in the middle of the ring. Not only that, but it was Floyd's first time at the weight and he was visibly slower and uncomfortable due to the pillow gloves. Not that it even matters, because again, De La Hoya was clearly beaten using your strategy.
2. Floyd isn't the same fighter who fought Castillo, open your eyes. He's more defensively responsible, and much less likely to get involved in phonebooth fights anymore. When was the last time you saw Mayweather regularly throw close range combinations like he did in that fight? The closest example is Cotto, and that was just him using the shoulder roll off the ropes. Not to mention Floyd was injured in that fight.
3. Actually, quite a few posters who's opinion I respect a lot on here see it the same way. You won't beat Floyd trying to pin him down and 'punch his arms'. The punch his arms genuinely makes me laugh, you're actually serious with that? You think punching Floyd's arms will have any effect at all? Any effect other than creating clear counter punching holes for him to exploit?
Guerrero and Canelo tried to execute the strategy I'm talking about. They had both done their homework, and they both knew it's the only way to challenge Floyd. Guerrero's was missing some of his counters by inches. A faster fight could of hurt Floyd with those shots, just like Mosley did. In the CENTER of the ring.
It's not about a 'pull counter' you need to stop watching so many highlights. Floyd uses the pull counter sparingly. The shots you can get him on are the left hooks he throws that are shoulder level, leaving the side of his head exposed. He throws that hook from low down, which is an opportunity that could be exploited, and an opportunity that was exploited by Mosley, who nearly dropped him with a counter right hand over it.
He also telegraphs the right hand quite a bit, but he gets away with it because he is so fast and so versatile defensively. Guerrero nailed him a few times early on in the right by countering the lead right hand with hard body shots and follow up head shots that scraped by. He wasn't fast enough to land those shots, but it was by far his best chance of landing a significant shot.