I'm surprised they didn't go further and remove alt, ctrl, etc. too. If this is going to be the sort of device (rather than a computer) you could dole out to grandmothers and the computer-illiterate/lazy (who could be a promising untapped demographic to get looking at Google ads - which I assume is one of the Chrome OS projects ultimate objectives) then removing the caps lock key makes perfect sense; there's hardly a reason for using caps in day to day web browsing, and - on occasion where it is - holding the shift key would suffice.
I've seen examples before, where those new to computers have had things made more awkward due to the caps lock key, e.g. accidentally pressing it and not realising, confused as to how to change it back to non-caps, or elderly people deliberately typing in caps all the time, since it's easier for them to read, unaware that it's considered poor etiquette.