Nobody says the hardware doesnt support it. If that were true, it wouldnt happen. What lies are you imagining Apple has told here? Supporting and supporting reliably are not the same thing. Older hardware truly DOES have less RAM and CPU power.
Apple says it MAY harm performance and cause crashes. Thats very true. It may. App developers complain about jailbreak-caused crashes (which then make the jailbreakers rate the app low). These JB modifications use RAM, and RAM is very tight on some iOS models. So of COURSE there will be an effect from that. And Apple wont be responsible for solving those crashes if they happen. Why should they be? If Apple supported jailbreaking, it would be a nightmare from them. And Apple would get the blame for resulting problems (slowdowns, crashes). So if they cant please you no matter what, at least they wont pay the bill for your tech support
This makes perfect sense. If you can reverse your modification, Apple will never know, and your warranty is intact. If your modification is irreversible, then of course Apple wont spend time/money fixing your problems. Thats standard with any product. Take heart: many kinds of failures would result in a warranty swap before any kind of check is done anyway.
Apple has not said jailbreaking ALWAYS voids your warranty. They have said it CAN. What could be more fair? Should they say, no matter what, well promise to fix any problems with your self-modified system?
People have a knee-jerk reaction against Apple (well... against a lot of things!) with no need to stop and check the real facts and reasons
I support jailbreaking but I certainly wont expect Apple to spend time/money on me if I choose to ignore their warnings.