True, but the assumption is that you'd get stuck on Mars with plenty of funding for supplies and reinforcements coming from Earth. Seems like a shaky basis upon which to plan such an extended vacation, considering we can barely keep an adequate supply of funding and supplies to everywhere on Earth as it is. Gambling that they'd be able to maintain a supply stream for the duration of my lifetime while on Mars is a pretty piss-poor gamble to make. Mars is no place to be when the supply ships suddenly stop coming because China decided to call in their debts and shut the whole thing down, or North Korea decided that shooting missiles at departing spacecraft would make for an entertaining fun-time activity.
What kind of supplies did you have in mind? Once a certain technology level is attained, one could manufacture quite a few things on Mars. Basic survival stuff (water, food, air) can all be manufactured there even with iterations on existing technology; water and air can be attained by tapping into the permafrost, food can be grown in hydroponics modules (or printed on a 3D printer when that technology becomes sophisticated enough). By the time a Mars colony happens, I'd bet that even meat could be grown in a lab. As for the other stuff, a Mars colony would never be self-sufficient in that regard unless we go there and get things up and running first - you can't have the infrastructure to support a colony if you're not willing to take the risk to go there and build the infrastructure to support a colony. There would be a dangerous period, yes, but I'd imagine a couple of decades would be enough to reduce the dependency on Terran imports to the point where in a pinch local Martian products would do. It's largely a matter of getting infrastructure up and running.
Also, last time I looked the US itself owned more US debt than China did (and who is to say that the US will be funding this? Mars One is Dutch), North Korea didn't have the technology for ASAT weapons (especially ones that can reach satellites that don't go over their heads - due to the Earth's rotation a Mars spacecraft is unlikely to be launched far enough north to reach the Korean peninsula) and even if they did, they know that would end worse for them than everybody else, and the whole thing was funded by private money anyway so none of us (in any nation) are required to care if we don't want to in the first place.
A Mars colony right now would be such a hilarious over-extension of resources, you would honest to God have to be insane to even contemplate it.
And what resources are those? Money? Do you have numbers to justify your claim of it being a "hilarious over-extension of resources?"