I'm sure a defensive lineman would like to demonstrate to you how to tackle "properly," with or without a helmet and pads. After you wake up, maybe you'll have more appreciation.
Real men learn how to tackle first (sure there is some blood spilled in the process, but these are real men) and after that they do not need helmets and hence they do not need pads either,
What makes rugby not as good of a spectator sport is that the players can't hit as hard and run as hard because they have no pads or helmet. Steve Young (a quarterback, by the way) received five concussions, and that's WITH a helmet. That means he got hit hard. In rugby you can't hit that hard, and the rules of the game themselves dictate when and how you can hit in the much slower game.
As far as being a spectator sport, football is faster, more enjoyable, and more cerebral (I play Madden football on a Nintendo Gamecube, very complicated and difficult, but nothing compared to the real NFL)
also real men are playing whole 80 minutes doing both defence and offence whithout running in panic off the field whenever there is change in ball possession.
I don't care if guys can run around for an hour nonstop. If I wanted to watch running boredum, I'd watch girls track or crosscountry--very boring. NFL is extemely complicated, and having different defensive and offensive players provides for specialization in a game that is very complex.
A wide receiver has to know all the plays, and there are lots and lots of them; he must have the skill to evade his defender through cuts, fakes, and simple outrunning; he must know how to block during a running play or block if his fellow receiver gets the ball; and most of all he must know how to make hard one-handed gymnastic catches from 50 yards away while three defenders are surrounding him.
And that's just a wide receiver. There's also runningbacks, tightends, quarterbacks..... There'a a long list of responsiblities for each and everyone one of these positions, and rugby doesn't have none of it.
You can see why Americans prefer a much faster, more enjoyable game that is filled with innovative plays and hard hits.
This is not to say rugby is a bad game. It's an improvement on soccer, certainly, after one day the guy got sick of just using his feet and picked up the ball and ran with it.
Put your defensive lineman into high-level rugby game and (1) he would be hardly able to touch the opposing player not speaking about tackling one,(2) the only way he would be able to stop advance is by bloodying his face and being stomped on by a merry group of 4-5 jolly guys at it still wont be enough to win the possession, (3)he will die from overwork in 15 minutes.
Football has its own niceties, however, only uninformed would consider its a superior wrt rugby.