Exactly. Maybe we'll muck up the climate here a bit and have to spend some resources to get it back on track, but Earth will never be less hospitable than Mars.
And we are probably hundreds of years away from being able to have a self-sufficient colony on Mars.
The only reason to attempt to settle Mars is because it represents the fattest international government contract that has ever existed - and I suspect that has always been the primary motivation for the Mars hucksters.