Why, to grow a competition?
Also imagine how a manager calling for sale of a unprofitable product would like if someone else made that project profitable.
Well, if they're not making enough profits off it (for Google scale), they could sell it off to some much smaller company. (They could avoid selling it to a rival of their size, like FB etc.). A much smaller company like that would hardly be likely to become a significant competitor to Google, except it they did many such acquisitions. Your point about manager not liking it is somewhat valid though, but even there, the manager who organized the sale could get the credit for bringing in some $Ms to the company :)
