It doesn't need to be alive to be beautiful. There is great peace and beauty in empty places. Mars has grand and majestic vistas: canyons and plains, dunes and mountains. Reducing it in your mind to a lifeless rock obscures the awe and wonder. It is the opposite of appreciation, it makes the idea small in you, worthless and not deserving of respect.
There are infinite similarly dead rocks in the universe.
Similar [dead rocks], or [similarly dead] rocks ?
Also, I think there are only finitely many eventually observable planets in the universe?
All of that requires an observer there to appreciate it. Messing up the scenery of Mars with industry is a champagne problem.
That is your perspective that it is beautiful. What if my perspective is that it is more beautiful inhabited, alive, and sustaining an ecosystem it probably hasn't for millions of years?
Beauty is really subjective.
You three sound like the argument between Sax Russell and Ann Clayborne in the Mars trilogy. If you haven't read them, I recommend them.