That would be a matter of opinion, which can differ depending on one's position.
No, it isn't.
Also, developers lose sales when someone rents or buys their game used, is Blockbuster then wrong?
No they don't. Game rentals use a different model. They don't get to just buy a $60 retail copy and rent it to people.
Developers lose sales when another developer's game overshadows there own, is that wrong?
Irrelevant. Buying game B doesn't entitle you to getting game A for free.