They are cheap for a reason, steam is popular so lot of people will buy the game at that price point. The creator of this software will see a one time bump because of HN but I doubt he will get a steady stream of income at least initially.

In the end everyone has to put food on the table.

What has that got to do with anything? If I see a game I want on Steam and I want it now, should I not buy it because it's not part of a sale?