Re: Destiny trilogy - pretty heavy spoilers
You're right, but it has been done without a reset and with some impact, (although not in Star Trek). I direct you to Doctor Who's Logopolis.Eh, it's different if it's not reset at the end, and is a planet we actually are familiar with. Destroy planet W from the XERT galaxy all you like, but blowing up the Earth counts for more. Especially since the body count would be heavy in characters we are already familiar with. Blow up eleventy trillion aliens from the Rth dimension, less impact on the reader (and the future of the storyline).