As requested, here are the reasons I like soccer (both playing and watching). Keep in mind that I like a good number of different sports for various reasons, and none of this means I think soccer is superior to other sports. This also only applies to soccer at a high level like we'll see during the World Cup.
Soccer is a team game and it's played on a huge field. It's really more about what you do while you don't have the ball than what you do with the ball. That's a very appealing aspect for me, but it also makes soccer hard to watch for many that don't know what to look for. While the best players are obviously very good with the ball, they're equally good (or better) without the ball.
In that way, it's also a game of patience, which I enjoy. You don't get many subs, so attacking players are often looking to wear the defenders down throughout the game so they can take advantage of what they hope is superior conditioning at the end of the game. All the passing has a point, as the team is looking for a shift in the defense so they can work the ball deeper into their opponent's side of the field. And like our own football, time of possession often relates to winning games.
Soccer is an elegant game. The tiniest step or shift of your weight can be enough to get you the space you need. Defenders have the advantage in soccer, so often it becomes a "game of inches" in that you only need to create half a foot of space to get the right pass off (usually a cross in front of the goal in these cases).
The game requires huge amounts of time and dedication if you're going to be good. Gaining the required endurance, strength, foot work, vision of the field, and skills with the ball is an ongoing commitment. Surprising to most is that your entire body needs to be strong, both lower and upper. The lower body is obvious, but upper body strength is required to maintain your balance and fend off opponents who try to muscle you off the ball. Soccer is actually a very physical game - far more physical than it looks while just watching it (nobody should compare it to something like football, though). None of that is really any different from other contact sports, but it still applies to soccer.
It's a strategic game, but a dynamic kind of strategy. Once you're out on the field, you're out there until halftime or the game's end. While the coach can yell a few directions, make a few changes, and so on, it's pretty much up to the players to adapt to what's going on. Tiny shifts in formation can make a huge difference in how your team plays. This also has a lot to do with movement off the ball.
I've already touched on this, but it's really the little things that matter in soccer. Mistime your run by half a second and you're offsides rather than 1v1 with the goalie. Force the defender to shift his weight wrong just a little and you win yourself that extra 6 inches needed to make the perfect cross. Mishit the ball by just a centimeter and you miss the goal by 10 feet rather than putting it in the corner. Don't make the right type of run to support your team's attack and all of a sudden their great series of one touch passes that shreds the defense ends with them losing the ball and being scored on with a counter attack. Very small things can have a quick and lasting impact on the game.
The one negative thing I will say about soccer is the diving, though believe it or not, it's gotten better in this WC. Diving is far worse than hamming up an injury to get a call, though that is still annoying. I will say that often collisions in soccer (like hard sliding tackles) really do hurt - especially if the spikes are up. There is a reason tackles with the spikes up is illegal...it doesn't matter where you get hit, being spiked in soccer is immensely painful for a little while and very dangerous. Unfortunately, people like Cristiano Ronaldo, who is one of the best and most popular players in the world - you can see him play for Portugal in the WC, will go down almost anytime they're touched. All they're doing is hurting the sport and being little bitches.
I'll go ahead and stop there. I'm sure I could list more reasons, but I think that's enough.
