The Republican Corporatists on the Supreme Court don’t really believe corporations are people. That’s just a legal fiction to cover their belief that the people who own and run corporations should have more power and rights than the rest of us. It’s a way of ensuring that the people with the most money get the most say in how the country gets run.
The thing is, those people don’t want the most say.
They want all the say.
And the Court’s decisions in Burwell v. Hobby Lobby and Harris v. Quinn help them along towards that goal.
On a related note, read The Trap in the Supreme Court’s “Narrow” Decisions by Jeffrey Toobin at the New Yorker.