Terrorism = Acts of violence with the purpose of instilling fear. Or something along those lines.
Doesn't matter if you agree with them. I sympathise fully with the root purpose of the PKK and the ETA, and possibly also the IRA. I find that their means sometimes undermine their cause, and it makes me somewhat uncomfortable to be aligned with them politically.
It's possible for people to do terrible things in the name of a good cause.
And "terrorist group" doesn't mean "the baddies" - that's just how it's used in America. Tarantino's jewish gang in Inglorious Basterds would be a text book terrorist organization, but terrorising Nazis is generally considered an okay thing to do.
Because they demand recognition via acts of terrorism.
Like we can have a discussion about how closely linked Rojava are to them but the PKK itself is undeniably a terrorist organization that engages in terror tactics to pursue its aims of recognition as an independent state.
Just because we might agree with the IRA in principle doesn’t change the fact that they did a fucking lot of car bombings, and the same principle applies here.