Sure, piling on the paradoxes can be annoying, but time travel is one of the most valuable tools/tropes an SF writer has when it comes to making metaphors {about regret/loss/redemption/The Road Not Taken}.
There was a brilliant DS9 time-travel episode with a totally wonky set-up --basically the was a planet with a time-differential field around it and Odo, Kira and Co. essentially crashland on a town full of their descendants.
The whole time-travel/SF set-up was in service of the character drama; an exploraion of Odo/Kira's budding relationship. It rocked.
And then there was More Tribbles, More Troubles, which was damn near perfect.