Your comment reads that you're angry at Github for not taking a more open source approach. That's a fine opinion to have, but it doesn't make sense to demonize them for being a for-profit company. They are not robbing anyone of anything.
Starving the competition with loss-leader tactics is not an unbeatable strategy. If, however, you don't have anything to offer other than a run of the mill payment processing platform, then yea, you're going to have a tough time beating someone who can cut costs. They have a feature you don't, you should lose.
$20 is less than a drop in the bucket, but $20 dollars for essentially a donation is another matter. For the companies that already contribute monetarily to open source, I don't think much changes. The unfortunate reality is that for companies who don't, not much changes.
Starving the competition with loss-leader tactics is not an unbeatable strategy. If, however, you don't have anything to offer other than a run of the mill payment processing platform, then yea, you're going to have a tough time beating someone who can cut costs. They have a feature you don't, you should lose.