Mars is fine as it is right now, but when you'll either render it Venus like due to pollution or render you destroy due to some thermo nuclear or biohazard shit and make it impossible for any percpective of life then we are talking about what we human can do with our stupidity
We won't further destroy Mars because we need it for further advancement into the Galaxy.
Sadly reaching Mars is one thing (as it achievable with near future technology if the resources and political power is put in place to do such a thing) but the rest of the galaxy is not happening anytime soon, it takes 10 months to reach Mars in it closest orbit to earth, an almost 3 years to do a round trip, to reach Jupiter it is 6 years ......ect to reach the star system Proxima centauri which is the closest star system to earth, it takes 80000+ years with our current technology
It's a several centuries if not mileniea challenge
if he haven't destroyed Earth yet what makes you think we would destroy Mars
it's good for human race to be stationed on more planets in case an asteroid destroys Earth
we didn't yet, but we are destroying it right now, being it directly or indirectly, directly but destroying whole ecosystem deforestations, destroying it resources ... and indirectly by pollution and global warming, not to mention that whole areas were destroyed by nuclear tests and accidents and more to come as nuclear power plants are getting older and older, not to mention other risks being it biological ones or technological ones....