Good morning all;
Who assigned the tasks ? PHB, of course. So Dilbert just picked and chose those that he could complete. Dilbert keeps his job because he doesn't fail doing those low priority tasks. Smart Dilbert, dumb PHB.
@nosnivel: You are right. I tried to picture the process they use to select low-priority and high-priority tasks and came to a conclusion that; yes, it is likely that there is no correlation between priority and reward.
He wouldn't get fired for that. PHB would have to reveal his management ability was called into question. He's more likely to "promote" Dilbert to an excruciatingly pointless task in the hope he'll quit.