OK so anyone fighting a stable tyrant country for political ends is a terrorist in your estimation. I think by some definition of "terrorist" you are correct.
But that's different than what the US uses for listed terrorist organizations.
And that's what I'm pointing out. The US is happy to support these groups when they're actually on board with eliminating tyrants. I think they publicly shit-talk China but low-key they are happy to list as terrorists any group that can credibly threaten them, because it buys them political points in dealing with China. I'm judging them with their value system in mind, which provides a better assessment of the motivations behind their actions than judging them with your value system in mind. That is, by the value system of the US government, if they actually support the overthrow of the government they will also not usually list as terrorists those who are tactically in a position to weaken the government in question, even though by your value system you might.
And I don't agree with your assessment that even if it ends with another tyrant in power, it was for nothing. The Kurds had a slice of relative freedom for a decade. In their estimation it was worth the violence. Obviously I agree with that, otherwise I wouldn't have fought for them. I always knew there was a good chance it ends with everyone slaughtered and I saw my share of artillery and rounds come at me, so I'm not just speaking as a hypothetical on behalf of someone else. Sometimes it's better to be alive for a moment than a slave for a lifetime. (The Chechens, also came to a similar conclusion, with similar ends and a period of relative freedom between the two Chechen wars; I find them to be a less palatable example though I don't blame them for the general idea behind their actions).