However, to someone for whom computers are mysterious and capricious black boxes which seem to have been put on this Earth solely to test their patience, "friendly" messages may carry tonal information which you take for granted:
* You did nothing wrong
* This is unintended and regrettable behavior, and we apologize
* Nothing is catastrophically broken
Consider that your mild irritation with a patronizing message is possibly preferable to some poor grandma hurling her computer out the window because "This program has performed an illegal operation and will be shut down."
Fortunately, there is infinite space to play in between "Gah"/"Well this is awkward!" and "This program has performed an illegal operation and will be shut down."
(While I appreciate what you do, hopefully this doesn't encourage you to spend time away from what all else that matters to you to write better comments.)
This is unintended and regrettable behavior, and we apologize
This is what the message should be. Maybe. I'd rather the software I use be apologetic than attempt to be my friend. That said, I'd settle for "we goofed, sorry" So it's not so much the tone (casual), but the content (own your defect, don't commiserate).