What's the difference between a soccer field and a football field?
Essentially they're both grass with posts & markings. You need a ball for both and off you go. The only other thing Americans need is helmets & body pads which shouldn't be that much more expensive. Are American Football posts & field markings so expensive? Come on.
Funding a soccer team is expensive too with all the training equipment too. You just don't see it. The money that goes into training equipment is very expensive. There's a lot of equipment you need. If you saw the cost of training equipment & facilities you would be shocked to the core.
In general though you can play both kinds of football on any old field with a ball. The only difference is the posts & helmets/pads. That's it. There are American Football teams over here but it's just not that popular compared to other sports. In some cases some less well off families won't be able to afford it but the same goes for other sports also with costs of boots, pads, kits etc. The cost issue affects all sports at a grass roots level.
Edit: Just remembered that there are plenty of rugby fields the world over that have essentially the same posts. That wouldn't stop American Football fans playing on there. It doesn't stop us playing Australian footy whose posts are different and we play with two less.
"The only difference is the posts and helmets/pads
." Again, equipment that isn't cheap. And again we're NOT talking about Europe as much as we're talking about 3rd world countries. There is training equipment for American football as well. This is in addition to the mandatory shoulder pads, helmet, and leg pads.
This is really simple. If you need more stuff, then it costs more money. Why bother when there is already a less expensive, more popular option that is totally ingrained in the culture? LOL Pretty obvious actually.
In our poor areas in the US, the equipment had to be donated. Really all equipment is donated by various people that encourage the sport. That's how cost prohibitive the sport is. The only thing I ever bought as a player were cleats and a mouthpiece (I live in Texas though where football is religion). But if I had to pay a few hundred of dollars to play the game...fuck that...I might have never played. Certainly poor families can't afford this cost. Fortunately in the US, they don't have to, but the reason they don't have to is because the game is extremely popular. This isn't the case in pretty much every other part of the world.
So yeah while the cost of equipment is a pretty good factor, no one said it's the only factor. To me it's pretty obvious it's about which sport each culture embraces. You guys love soccer. We don't. (and vice versa with exceptions on both sides obviously) Cost compounds this.