@Oninoshiko
"Search a loss-leader."
And that means nothing. Markets can exist around loss-leaders. Look at the games console market. The majority of games consoles are loss-leaders for the sales of video games, yet there are analysts whose entire careers are based on watching the games console market.
"Google is an advertising company. Google users are not their clents, Adwords users are. even if they do somthing that we all love, if adwords users hate it (and start to leave because of it) it wont stay around."
Sounds a lot like the broadcast television market. You only neglected to mention the equally important third leg of the triangle. Google's users are like television's watchers -- they're the audience -- i.e, the product sold to the advertisers. If people start to flock to another search engine, just as if a network's ratings drop, the advertisers will lose. So Google has to sell search as much as it sells advertising, just as broadcasters have to sell their shows as much as they sell ad spots.
So search is as much a market as broadcast television is. That's why Google continues to invest in its search technology and why broadcasters continue to invest in new programming.