You're right. But I don't think profit is everyone's first concern. The Kim dynasty needs the DPRK army as a tool of internal control more than it does for defense.

The benefits that gives them are very much a type of profit.

And a few million bucks isn't hard to come by when you're in control of an entire country

Even if it's as poor as NK, the guy who commands it can have more material riches than most of us can really consider