Have to agree with the other two replies. Having the cooldown timer reduces griefing of fellow players attempting to do STFs and fleet actions, and to challenge players on working through an event instead of giving up and restarting. This penalty is made clear when one tries to leave one of these events. The cooldown applies to all STFs and many fleet actions.
The devs put this in place; there's nothing to fix, it's Working As Intended.
Lesson learned. Be careful what you click, and don't leave an STF or fleet action lightly. Otherwise, you'll have to find something else to do for the next hour.
I don't care how long you've been playing. I only care about how you play.
And remember to follow the rules.