Ah, now for once I actually half agree with you on something
This is in fact not a bug, but an upstream Ubuntu design decision made for Lucid and obviously inherited by Maverick. Notice when you right click on a removable storage device on the desktop that you don't have an "Unmount" option like you do for hard disks? That was there prior to Lucid. The Unmount option us the only
option (out of the three: unmount, safely remove and eject) which will trigger Nautilus to check if there is still trash on the drive, and if so, prompt you to remove it. They decided that having three options to do almost the same thing was confusing so they removed the only really useful one. Eject is meaningless for anything except optical storage yet still shows up, and safely remove unmounts all partitions on the drive (not that you normally have more than one on flash memory cards anyway) and powers down the drive but doesn't prompt to empty trash. Unmount only unmounts one partition and does not power down the drive, but it will prompt about trash. Now if you open up a Nautilus window and click the little eject button next to the drive, this will
trigger the Unmount and prompt to empty trash, but if you've made it to this step you may as well just click "empty trash" anyway. I was very
displeased about the removal of this context menu option.
On a side note, the "desktop trash" is really just an aggregated display of the trash on all drives. There is no single location for trash, as each drive stores its own trash. If you have an empty trash and then plug in a flash drive with deleted files, you'll see the trash can fill up. There is a good reason that every operating system does this: moving or copying data in and out of a central trash location every time you delete or restore something is going to waste a lot of time and bog down system performance in the process. It is much faster to simply modify the file path and leave them where they are physically on the drive.