Sure they should optimize it, but taking away noob features that should be basic to all OSs is lame.
Let's look at it this way: if apple can make something as great as Spotlight (which took ages for windows to catch up on, and it still sucks), then they should have the ability to restore from the trash. Even the prorgam AppDelete has a feature for restoring files from the Trash, so let's not pretend that this is some monster feature that's going to bring us down to the level of vista.
Speaking of Spotlight, this is a scenario I've run into where Restore from the Trash would be useful:
I search something in Spotlight and I dump it. Oh, darn, I noticed there are a couple other files with the same name further down the list, and I have dumped the wrong one. I want to restore from the Trash - but wait - I don't know from where the file came! Darn, no Restore from Trash either...
On an OS as great as OSX, I really shouldn't have to write down the directories of files to keep track of them myself. What we're talking about for adding a Restore from Trash is a mere list of text files and a way to keep track of them. Even if you had 1000 items on the list, you're still talking about KBs of space.
Just my little rant. If I'm looking for tip-top performance to get every last FPS in a game, I'd gladly run a minimal kernel + X. That's where I don't mind my OS lacking basic features like Restore from Trash.
Again, not a deal-breaker, but certainly something that would be nice to see.