How so? There are no legal resources for acquiring Z/OS as a student without paying absurd (for a student) prices.

You could take a class for cheaper, but formal classes are poor substitute for interacting with the system on your own terms. (Ask any programmer)

You seem to reason that anything that is not available on your terms is fair game for piracy.

IBM can do whatever they like with their IP.

I believe the point is that if you want to play with it, your only choice is piracy, not that you must pirate it.

Since, in practice, nobody's going to pirate it either, that means there's no way to learn about it on your own. That's shutting down a very big free training mechanism for IBM, though it's probably too late to do anything about that now.

Oh thanks for pointing that out.

Karunamon didn't imply it to be fair game, he stated that it's too expensive to afford for learning for most people, which seems to be a simple fact. He also stated that it's a shame, which can mean either that it's a shame that you can't learn, or a shame that you're to infringe, and if taken to mean the latter that makes it seem like you're actually in violent agreement with him.