because there are so few of them. In my experience, and this is only my experience, nothing else, not a touchdown, three-pointer, run, etc, is as exhilarating on its own merits as a goal. You go into the game knowing that there will only be a few goals scored, at most. You hope your team scores a couple, maybe even three. And when your team does score, it is a huge deal. When the other team scores, it is crushing. In context other scores can be more exciting, goals are more exciting in context too, but for me it was the rarity of the score that made it so euphoric.
All the more goals! suggestions have been made before: ditch offsides! bigger goals! no goalkeepers! etc. Every once in a while Americans get to brainstorming how they can make soccer better (probably around World Cups). Offsides can be a tough rule to process and accept. It took me a little while. My first World Cup I couldn't understand why they didn't just abolish it (yes, there were novices suggesting all of these changes then too), eventually you just get it, understand it, and accept it.
Soccer fandom probably comes when you finally begin to appreciate what happens in-between goals. It takes, maybe, thirty seconds from any given time in a game to a potential scoring opportunity. No matter where you are on the field, no matter who has the ball, a score can happen before the minute is out. Just like a home run can occur with every pitch. To say soccer only has a handful of scoring opportunities while baseball has one every single pitch is faulty. There isn't a home run or a base hit on every pitch. A lot of pitches are balls, foul balls, strikes with no swing, etc. If those count as scoring opportunities there isn't a moment in a soccer game where there is not a scoring opportunity. And as you watch more games and see what players and teams can do and the various ways goals can be scored your imagination starts to open up and you begin to see what the players are attempting and all the ways that whatever is happening on the field right now can lead to a goal. When you are starting out, it's hard to tell.
The World Cup is the perfect time to attempt to get into soccer, just because of the number of games. You can watch a game a day for a month. If you get into it during club season it's a game a week. You can get a season's worth of games in one month with the Cup. If one or two games pique your interest in the least bit, which if you are posting about it there is a good chance it does, give it some more chances. Catch a few more games. I grew up with football, basketball, and baseball ingrained into my consciousness from my earliest memories. I don't even remember learning the rules to those games. It's like I always knew them. I didn't question the rules because...they just were the rules. I didn't learn soccer until I was in my twenties. I had to learn the rules and I had to take a lot of things for granted at first until everything coalesced for me.