Reputation isn't a race, it is there so I know how much I can trust someone's answer.
Ideally, a high reputation means someone has made a lot of points others agreed with, so they upvoted. Ok, it's not a perfect indicator for knowledge, but IME it's pretty good.
However, if you want to take this as a race, go ahead. Pick some popular tag in a field you know a lot about, keep updating the tag's page, and give many damn good answers. It isn't too hard to get, say, 30k per year, on answers alone. If you try harder, you can certainly get past 50k, and if you're really desperate, hitting the rep cap daily, and raking in extra rep from accepts (as Jon does), you can even make 70k.
What do you mean, "this is work?" Why do you think it's called "reputation?"