If you can fund a Mars colonization mission all by yourself, then more power to you. But I just don't think it's possible, at least not any time soon. As a species, we haven't even managed to do any better than landing 3 men on our very nearby Moon for very short missions. We have zero experience in building and living in actual offworld habitats. It's never been done, not even in the one place where it's so close by that a rescue mission wouldn't be hard to do. The closest we've come is Biosphere II, a glass building in the Arizona desert, and that was a big failure.
It's too late to edit this, but I just want to qualify it: we have zero experience building and living in habitats on other celestial bodies. A small space station in low-Earth orbit within the Van Allen radiation-protection belts doesn't really count.
Funding be damned. No one is asking you to work your arse off Interstellar style to fund a secret program to fund humanity and get us out of here. And no-one is asking the US government to pump a trillion into setting up colonies out there. But it will happen - and there will be commercial starts to it - asteroid mining, with initial small numbers of support personnel up there, then maybe a few habs. Maybe it will take generations; or maybe we'll be wiped out before then. But it is either part of the inevitable march of the story of our civilisation; or there won't be a civilisation to talk about
