system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does Facebook change their look so much, and why are they forcing people to switch to timeline, AND when they make these changes why does it sometimes make your privacy settings go back to the default ones? 

I mean, I know these changes are things you get used to...but I HATE timeline. I'd like Facebook to stay the same or at least similar. The changes never seem to make things better, more efficient, or even more appealing to the eye. They're just a bother. What the hell, Facebook?
gpt
Mainly to increase the presence of ads, likelihood to click ads, and availability of ads.

Also to provide value so people will keep using facebook.

More shared information increases likelihood of others using facebook and data available to advertisers.