DadJoke007: They probably think that the end result will result in a lower net profit in the long run. It's not like they do it out of spite for GOG or the customers, money is money.
While I think what you're saying is correct in a purely economic sense, I'm not ruling out other motives outside the bounds of economically rational decisionmaking. It just seems fishy to me considering how many games miss the store, that all of those developers would come to the same conclusion about it being a lower net profit long-term (also it appears to me the trend in this business, among others, is to focus on short-term even at the expense of long-term).