i'm a senior software developer at a LAMP shop; i write a lot of SQL for ad-hoc queries and what-not. i capitalize SQL queries, even in my ad-hoc queries (it's a good habit to get into if only for readability), but i don't ever use the caps lock key. it is more efficient for me to hold down the shift key (which is closer to my pinky than the caps lock key) while continuing to type at the same pace than it is to stop and press and release the caps lock key. i suspect this is likely the case with most people who are able to type at any reasonable pace.
so, your example fails to convince.
the only reason i can see for keeping the caps lock key is for old and/or braindead systems that don't speak anything but uppercase.