Pardon me if I'm being presumptuous but I think the problem may be in the use of the word "king". "King" suggests that there's one, supreme factor in the making of a profitable web site, content, and if you've got content you've got all you need for success.

A better metaphor might be an arch.

Content's obviously important, it's the keystone of the arch, but the other stones in the arch are also critical if the arch is to stand.

If your content is terrific but you don't market it around, let people know you exist, and give them the opportunity to decide if you're offering something that they might find interesting then you won't get any, or much, traffic. No traffic, no revenue so building and maintaining traffic is important.

Another of the stones in this arch is the revenue source. If the revenue derives from Adsense then you ought to understand how it works so you can craft the best strategy for maximizing income. If you're selling something then you've got to understand what gets people to buy and craft a strategy for maximizing purchases.

Design's also important since a butt-ugly site is liable to turn people off despite the quality of your content. People make assumptions from appearance. If your site looks like you designed it while on acid, people will leave before they give you an honest look. Too bad, it's your responsibility to make the view pleasant or, at least, inoffensive.

Trouble is, we like to do what we're good at and avoid the things we're not so good at.

If you're a graphic arts-type you might spend two weeks tweaking the design of the site until it's frikkin' awesome. An aesthetic experience. But if you don't have decent content then what's the reason for people to stay, return or tout your site to their friends? If you can't be bothered with all that marketing crap then who's going to see your work-of-art site and if you don't have an eye on the revenue stream you may find yourself with plenty of traffic and not much else. That sucks.

So Radu, pardon me if I've overstepped my bounds but it seems to me that the message you were getting across is that to have a profitable web site, to make a real business out if it, you've got to do everything, not just the things you enjoy doing.