The article seems overly critical of a cutting edge development for humanity.
Even the scientist they sourced, Chris McKay, said "If you drive the costs of transportation down by four orders of magnitude, then everything becomes easy".
Sure, radiation has some effect, but "it's not a showstopper" (once again their source). http://www.space.com/24731-mars-radiation-curiosity-rover.html shows that the average radiation exposure is around 300 mSv over 180 days. This is without any attempt at shielding the rover from radiation exposure. It's likely not a very difficult problem to tackle (compared to the amount of work that's being done at SpaceX currently).
Then there's talk about "microgravity" and "80 days in space for the trip". Well humans have spent much longer in space: https://en.wikipedia.org/wiki/List_of_spaceflight_records#Most_time_in_space
It seems like a bunch of small problems are repackaged into a critique of SpaceX, and most of those problems aren't even what SpaceX is trying to solve. They are a transportation company, this is a huge project, there is no way they can solve everything, right now. And solving the issue of how to live on Mars is completely pointless when you can't get there in the first place. The solutions will likely also be partially determined by how we get there.
Bogging your self down with small problems that can be solved later isn't the way to get stuff done. I guess that's why Musk has a track record of completing world changing (and I mean this literally) projects.
Yes, there's "a lot left to figure out", but who thinks there isn't? This will likely be one of the biggest and most important events in human history, and will improve the outlook of our species considerably.