Clearly the author doesn't understand how capitalism works. If Apple can pick you up by the neck, turn you upside down, and shake whatever extra money it can from you then it absolutely will do so.

The problem is that one indie developer doesn't have any power over Apple... so they can go fuck themselves. The developer is granted the opportunity to grovel at the feet of their betters (richers) and pray that they are allowed to keep enough of their own crop to survive the winter. If they don't survive... then some other dev will probably jump at the chance to take part in the "free market" and demonstrate their worth.