The truths we are discusssing about Mars also weigh negatively on the silly “science” reports about humans having human colonies on Mars. That would not be possible unless they spent most of their time (70-80-90%) underground and only went to the surface in space suits. And that is just one set of issues that leaves out sufficient water and oxygen.
There are not enough humans that want to live like that.
Mars will always be science project for humans, never a colony.
I had to do a presentation about Mars, and found it to be a fascinating subject. If Mars had an atmosphere that wasn't corrosive, but not necessarily breathable, there could be some possibilities. With no shield from the Sun, it is like you said, a science experiment at best.
This solar system is, aside from Earth, an inhospitable dry hole. Venus could have had possibilities, temperature extremes aside, if the atmosphere wasn't so violent and toxic.
Actually (assuming Mars does still have some ice left), a pretty significant number of humans live worse, now. And that leaves out us tossing nukes around...