Obviously there are some questions I can't answer, nor am I that interested in them (e.g. facebook). I tried adding them to the ignored tags list, but they just show up slightly grey. I was expecting it to be StackOverflow like, and I would not see them at all.
Is this a bug?
There's an option in your preferences called "Hide Ignored Tags". You need this marked in order for the tags to be hidden, rather than just greyed out.
SO has some more rigorous filtering of the front page so that it doesn't show ignored tags and prefers interesting tags. The idea being that they want to present a list of questions that are more interesting to the user. That, and just showing "latest" like the other SE sites would be a lot of noise due to the sheer amount of traffic they get.
http://blog.stackoverflow.com/2010/11/stack-overflow-homepage-changes/
So the reason you're seeing them here and not there is due to the filtering, unless you turned on that "hide ignored tags" flag that was brought up already.
