I'm with you, up until here. If I buy some content (e-book, movie, TV show, etc.), and then DRM malfunctions or is senselessly restrictive (client doesn't exist for some platform, etc.), I feel it is justifiable to "pirate" the content which I paid for. Particularly in the case of malfunctioning DRM (which is unfortunately common for PC games these days), it is the provider who failed to hold up their end of the bargain (whatever their EULA may say).
But of all the things studios do, deciding where to sell or not sell content is something that they actually have every right to do. We are entitled to content we paid for, but are not entitled to content just because it exists. If HBO doesn't want to release Game of Thrones during the season to Amazon, etc. because they want people to watch it on their network, what right do I have to steal it because I don't want to pay for cable?