At the elite level, you would have a bunch of specialists standing around in front of the goal, waiting for a long pass to arrive.
Which is why hockey also has their offside rule.
That's the answer I get from the knowledgeable soccer dads on the team, and I'm inclined to credit it. But still: if a team parked a couple of position specialists around the goal, it would be sacrificing field players, possession, and chances. I wonder where the balance would sort out.
My other random amateur thought is that soccer perhaps needs another official or two on the field. It's a game where ball position shifts frequently, the field reverses, and with a long kick or two, the ball is one the other side of the field and 40 yards the other direction. I don't know how a referee can be expected to keep good position. It is also next to impossible for a referee to see much happening off the ball. The head stomp on Carli Lloyd in the Olympics is a good example. Given that so many of the fouls in soccer involve inherently tough calls on bumping and tripping, it has to be a brutally hard game to call at the distance that is commonly required of a soccer ref.
Basketball puts three officials on a short court to watch 10 players, and it still has controversies. Football also has 22 players on a comparably sized field, and it has a referee, umpire, head linesman, line judge, field judge, back judge, and side judge. That's in a stop motion game where most of the contact is concentrated on the line of scrimmage. It still takes a perimeter of officials stationed around the play to watch everything.
I've never played the game, so my opinion is isn't worth much. But from limited experience, soccer officiating seems to be a weak spot.