In Starship Troopers it always bugged me that they didn't simply nuke the planet from orbit.
Yeah, they wanted to capture a brain bug, but if they nuked the planet from orbit they wouldn't need to, except perhaps simply as a scientific curiosity.
A lot of films with proficient space travel seem to gloss over the fact that an efficient and powerful space engine is exactly the same technology needed to pull off a planet-wide kinetic Exterminatus. Assuming you don't want to retrieve something from the biosphere of a planet all you have to do to wipe out a planet is find a sufficiently large asteroid a sufficiently far distance away, accelerate it to near light speed, and then go dark. The end result is a chunk of rock that is nigh-undetectable and by the time it is close enough to be detectable it doesn't make any difference because all blowing it up would do is increase the level of destruction.
Of course when the alternative is for the story line to be that all the governments suddenly panic, make an announcement about how we are all going to be dead in an hour, and then have 99% of all life be exterminated instantly, followed by the aliens landing on the desolate planet and beginning mining operations, it's pretty easy to see why they ignore that fact.
I think Frozen is one of those movies you're supposed to like because Academy Awards and stuff. But to tell the truth I found it quite underwhelming and some of the singing was just terribad, and I don't really care for the characters, and I'm still annoyed that they were all so eager to cash in with Once Upon a Time (which is itself a huge Disney cash-in but at least it was somewhat quirky, the Frozen crossover is just completely in-your-face).
I liked it because it was the first time an animated Disney film really pushed some of the standard "fairy tale" boundaries that they usually follow. It simultaneously managed to hit the both the
"first evil prince" and "first act of non-romantic true love"
marks, as well as managing to hit the rare "two strong female leads" mark as well.