phys.org : Reports from “Humans 2 Mars Summit” suggest dust may prevent human settlement of Mars by Bob Yirka
…. perchlorates appear to be widespread on the planet’s surface. The fine dust material produced by perchloric acid has been known to cause thyroid problems in people here on Earth.
Just as problematic, … is gypsum…. been known to cause a condition similar to black lung in coal miners in people exposed to it for long periods of time.
… known presence of silicates on the Martian surface—if breathed-in they can cause reactions with water in the lungs and result in the creation of harmful chemicals.
Martian dust could pose health hazards because of the difficulty of removing it from space suits and boots. … fear the dust would build up in air filters and living quarters, adding yet another life threatening element to the list of other known hazards (traveling and landing safely, exposure to radiation and cosmic rays, etc.) for the people who seek to colonize the planet.
You can always find some pretext for why not to do something.
This sort of narrow thinking is why it the Mars colonization effort by somewhat older unworried warriors is a great idea, they will lead the way, they may die earlier…will almost certainly die earlier than they would on Earth but in the big picture they will be immortal.
I think that a commercial fly by of Mars possibly convoying with early colony equipment makes a lot of sense. Drop off a 3D printer to start fabbing buildings or building parts. The fly by would work on the tech of getting there and of living in space for long periods. Multiple (4 in a Bigelow Cross?) inflatable Bigelow modules would make a light weight but spacious habitat that one or two couples could live in for the time needed. I would boost and decelerate the complex with an earth orbital tug and have minimal onboard propulsion since its pointless mass to take with you. With the right kit of science and DIY they would keep busy doing various types of investigation the whole time.
All possible in the next twenty years, tenish if we really pushed, and I think we could commercial/ kick start/survivor fund the whole bloody thing…