You know, I agree with the idea this isn't a big deal, or at least, it might not be eventually.
The bar is programmable, so I would expect that applications like iTerm will write in support for it and they probably would include an ESC key on the bar. It would be nice if Apple had thought of this and Terminal.app already did that. Maybe they didn't think about that, but my guess is that they work mostly in Xcode.
Then there is the suggestion from someone else in the comments to remap the Caps Lock key to ESC which might be something I try even though I pretty much use full keyboards. The ESC key on home row might be a great idea.
