[DarthGhandi]

There's probably a better word but it resonates with some people.

The desire to preserve other planets for the remote chance that there's life there and we can study it before turning up anyway and ruining things is misguided. We are the only known life in the universe, it's incredibly irresponsible to not propagate such things (just in case)

[eru]

Perhaps 'moral responsibility'?

[wizzwizz4]

Unless we end up killing life that already exists there.

[scollet]

The aliens can make a movie about it.