Wasn't Columbus the fellow who found most "Indians" taken captive for the purpose of forced labour made poor slaves, but the young girls could be sold profitably as sex slaves? Most disease introduction may have been accident, but some was deliberate. Sure, societies could be brutal in the Americas - but some more so than others. Didn't some early N. American colonists get generous help in times of desperation?
It is my hope that if/when the Mars colonies have grown large enough to govern themselves, those on Earth allow them to without all the fuss.
Should unpaid debts to the Earth investors and equipment suppliers be allowed to be written off as part of this bid for self rule? Sure, all the fictional stories of space colonies in revolt start with being cruelly treated by a distant, uncaring Earth Tyranny, making it a noble struggle for Liberty and Justice... but I doubt that will be the case. Watching profits go to distant financiers, who are oddly reluctant to allow those debts and obligations to go unpaid, may be very frustrating but I don't think America would have been a failed state or their European settler populations oppressed had that Revolution not occur. Canada did alright after all.
So, should those who support continuing the status quo be - like Loyalists after the American Revolution - declared traitors (neatly inverting the reality that Revolutionaries were the traitors), stripped of property and forced to flee or stay and be brutalised?