You just don't enjoy the NFL cos you dont understand the game and can't appreciate the athleticism for the size of the players.
I'll admit, they can move alright for the fat lards that they are. Probably helps they only spend a minimal amount of time on field, and the second they're required to change from attack to defense, they get a breather and some other fat lard replaces them.
The fella you posted, Vernon or whatever, is obviously not one of the aforementioned fat lards. He probably is quicker than most our outside backs, and stronger than our forwards. But I'd put my leftie on it that he would be as useless as tits on a bull in the NRL. Something that size cannot run around for 80 minutes attacking and defending until it hurts. He'd be a fantastic impact player for 15 minutes though, I'm sure - but with interchange limits, he wouldn't be worth it, especially since the chances of him evolving into something more than 15 minutes of hell per game would be slim to none.
But I don't wanna compare NFL and NRL, they're completely different games. One is about 34 blokes going hell for leather for 80 minutes matching skill, toughness, endurance, smarts and a whole host of other qualities against each other. And one game is about 8-10 specialty teams containing bugger knows how many people in total going stop-start against each other in 10 minute bursts.
NFL - An 80 minute game that takes 4 hours to complete.