In companies big enough to have both in quite different groups, I've found that the DBAs don't know much about the database layout and thus doing things on the DB's CLI is generally an exercise in "Do I Know What I'm Doing?" At the least, a DBA should have ready access to the Operations' restore system if he bolluxes something up. Yes, I've seen that done, too.

DB Programmers, OTOH, have more problems.

I'm one of the latter. I make sure I modify my MySQL prompt to tell me what DB I'm on. I also have enough discipline to only use the actual Prod Master DB for changes; I have a separate connection to a slave for looking at the data, and a dev database all of my own for playing with the data.

Wade.