I feel your philosophy.
Optimistically thinking, humans could achieve colonization of both space ships and foreign planets but given our history, I wouldn't hold my breath. I mean if we completely ravished this planet in a mere 200 years of industrialization then what are the odds we would pull off a colony on Mars, * edit* without a change of ideologies?
Granted, my scientific knowledge base is limited to rudimentary general education courses and tons of Ted's talks and documentaries of the sort but I'm confident in my historical knowledge base that without a huge shift in human behavior we have abysmal odds at space colonization that is capable of sustaining the human race.