A flat icon set for OS X

Nice job! Just missing a Facebook icon for my Facebook SSB.

I like them.. They might just get used if OS X goes flat..

I may be in the minority, but these feel really boring and dull to me. I think there is a way to have a "flat" icon while still providing some depth to them.

I've also seen dozens and dozens of flat icon sets for Android that basically have this same exact look. Just go to XDA or the Play Store and search "flat icons", I'm sure you'll find a bunch that have a mix of these designs.

Mac isn't bad in the historic flat design department either: https://twitter.com/JonyIveParody/status/486510620276441088/...

Philosophically or practically: What's the justification for nearly everyone switching to flat design? Is there any articulable reason it's "better" than the rich, three-dimensional style[1] that was previously popular? Or is it just an arbitrary trend?

Some say the change is driven by high-DPI displays. I disagree. I don't see any intrinsic reason that flat designs look better than rich, three-dimensional designs on a high-DPI display. Without a doubt, flat can look nice, but so can things like this:

http://www.sequelpro.com/blog/wp-content/uploads/2013/01/seq...

Another justification I've heard is that it's a reaction to the excesses of the previous trend. People often point to the leather motif in certain Apple applications as an example of such excess. But first of all, those examples are outliers; few designs actually went that far. Second, the existence of a questionable use of a given style is not an effective argument against that style in general. Third, "some things were extremely 3d, so now we'll be extremely flat" seems like contrarianism for contrarianism's sake.

[1] Some call this skeuomorphism. I tend not to, because the term technically means something narrower than what we're talking about: http://en.wikipedia.org/wiki/Skeuomorph