While it would technically classify as "abuse" to prevent death from falling off cliffs, or the end of the world, (at least those caused by deficiencies of the movement system, like when it keeps on running even if you let go of the key) by using /unstick, I believe the real abuse that caused this change was the behaviour that Kerol mentioned in the linked to post (where the use of /unstick is, IMO, the less severe abuse compared to the unreachable spellcaster trick), and the avoiding of damage when in a fight.
This is just as abusive as using /die to warp from the BD to Hydlaa, or even to Ojaveda in case of an Enkidukai. I seem to be the only one who's stupid enough to actually run back each time.
Maybe it would be an option to allow the use of /die only once every RL hour, or even only once a day. This is IMNSHO justified since /die hardly sees any non-abusive use, ever. Of course, that wouldn't prevent people from just jumping off a cliff.

As far as being punished for other people's wrongdoings goes... indeed it is exactly that. However, it emphasizes something that people conveniently ignore and which causes a great deal of the damage to society we see every day, IRL: lack of social checking, or courage. People see others doing things they know are wrong and that are unacceptable, yet they don't bother to even try to change it. In PS, this is much much easier and involves much smaller risk than IRL, so it's inexcusable that people don't bother protecting their game from the abusers. So you are in fact being punished for
your very own neglect of your social responsibility.

Sending a simple /tell to the abuser is an option, just don't be the silent majority. If they become singled out, they'll stop.