Well, since we are all discussing the apparent inability of Macs and iOS devices to communicate via AirDrop, I'll chime in with my own opinion.
I came here the same way most others did, by googling 'iPhone 5 airdrop can't see my Mac'. It looks like Apple has become the victim of their own success. Most of us expected this functionality from Apple; the feature is called "AirDrop" in both systems, so, within Apple's logic of eco-system transparency across the board, it would only be natural for AirDrop to work across all devices, just like iCloud, or Messages. I am not at all surprised at the incredulity of others here (the colloquial WTFs about the incompatibility of two different AirDrops -- iOS and Mac).
To add my own use-case scenario, the utility of cross-platform AirDrop isn't just so that you can move your files form your iPhone onto your MacBook or iMac. Many times I wanted to quickly send a file from my iMac to a friend with an iPhone (for example, I just finished a quick recording of our rehearsal and would like to send the file to all the band mates' iPhones). While there are other options here (e-mailing, sharing on iCloud, etc), AirDrop seems, at least to me, the simplest one with the lowest number of steps (drag the file onto the AirDrop -- that's it!). Similar case is when I want to give a file form my iPhone (a VoiceMemo recording, for example) to my friend with a MacBook Air. By far the most elegant and simplest way would be by AirDrop, but now I have to use various work-arounds (sharing on DropBox, having him open my e-mail message, follow the DropBox web linke, etc...).
AirDrop is an incredibly ingenious concept, and as such adds an excellent way for Macs to exchange individual files between each other (as well as iOS devices between themselves). However, its usability (and consequently the usage rate) would go through the roof it Apple engineers were to figure out a way to integrate seamlessly the two platforms.
My message to Apple's feedback link has already been sent. Perhaps they'll think about it.