Of course you're right, but I think the only one who did it out of depression was Luna, and that wasn't in the comic. (I think she admitted as much when going out with Melna.)
Naturally. Orcs may not know how to solve their problems and resort to alcohol because of it, but, hell, are they awesome.The integrity of Orcs can't be damaged and they can therefore drink themselves into a stupor as often as they want.
(We should, however, do our best to help them where they clearly can't help themselves. I call this the Pink Man's Burden.)