From my perspective, soccer had three basic flaws that make it difficult to enjoy it as a spectator sport:
1. It's one of only two sports (football being the other) where the clock runs while the ball is out of play, after a whistle has blown to stop play, etc. As you correctly pointed out about the NFL, this really slows the game down and removes a lot of the urgency of playing the game for real.
2. Related to #1, I have a hard time taking a sport seriously when the referee on the field is the only one who knows the official time, and is the sole arbiter of how much "stopped time" is added at the end of the game. This is indicative of a sport that is so archaic that it was designed to be timed with an hourglass or a sundial.
3. Free substitution would go a long way toward making soccer an exciting game. The implementation of free substitution -- even "on the fly" during the course of play while the clock is running -- in professional hockey back in the early 20th century is what helped define the sport today. Previously it had been a slower, almost gentlemanly sport ... much like soccer on ice. Adding the free substitution turned it into the fast-paced, frenetic game you see today.
And I don't think I'm going out on a limb here by suggesting that hockey is a sport where an athlete has to be better-conditioned than soccer.
Free substitution is a good idea. I grant you that.
Four or five players running hard still beats sitting on your ass half the game.
I’m glad you like hockey, but hockey players (like in water polo) also have a Newtonian advantage. Water polo guys have buoyancy and hockey has less friction and inertia to overcome.
Maybe the timing of the game should bother me, but for some reason it just doesn’t. I do grant you that the referee in soccer has a lot of leeway in assessing penalties. What bothers me more is match fixing and corruption in FIFA.
When we [the USA] has a viable team ... one that can win. Or, better yet, one that shocks us by knocking out of the court, every American will be on board for soccer.
But, as long as we lag, and never win a game, we don’t care.