I played the demo for the first one on PC a few months ago and didn't see the fuss.
No there isn't really anything special about it, it only got popular cause it was a fun time waster for your phone and never really got big on PC mainly just Phones and Tablets but they still made them for PC so they could have them on all platforms. And for ppl complaining about the $5 for it shouldn't really complain cause Angry Birds has been $5 on PC for a very long time it is just now they brought it to Steam.
I do understand why Rovio is selling AB on Steam and other places not mobile as I've seen parents buying the physical DVD's to their kids. Not everyone has afford or need to buy their kids an expensive phone, but those birds still are popular, so the next best thing is to sell the game on consoles and PC. And it's not like they're asking premium price of the game.
And I do like to throw those birds myself as well, I'm still in the middle of AB:SW on my tablet.
Yeah true except what some people don't know is that Angry Birds has been on PC for a few years so it is nothing new and same with the $5 price tag, the only thing new now is that it is on Steam which I am happy about cause I like playing AB as a good time waster and it's nice not to have to go to their site to buy it when I can now buy it on the platform I am on the most.