Actually, I can't remember if I read it before, but it gets at the same thing I was alluding to. For as much as we tout humanity's curiosity and desire to explore, it really isn't universal. Most of humanity is simply content and lacks the desire to better themselves.

Its the drivers and the dreamers who are pushing the boundaries and will hopefully take us into space. I suspect if it ever does happen colonies will self select out the complacent.

James SA Corey's expanse series addresses this to some degree. Earth's population is stagnant and living on "basic" If you want to work you have to test for it, otherwise its a life on basic. Elsewhere Mars and other asteroid colonies don't have the luxery of supporting people on basic, therefore humanity has split into 3 basic camps (3 because Mars is as suspect as Earth to the other colonists).

I'm in the hoping we populate the solar system camp. I don't think we need to look beyond unless FTL drives somehow spring into existence. The distances are just too vast.

Profit, slaves, and missionary work weren't the only reason the new world was explored and populated. Several groups were fleeing oppressive governments and/or religious persecution. I could see all sorts of motives for trying to get off earth. Unfortunately its a death sentence. Until infrastructure and technology make living off earth sustainable, ain't nobody getting off this planet. Personally I give us less than 50/50 odds of ever getting a self-sustaining colony started. We are just as likely to sophocate mankind on this planet as we are getting off. I'm normally an optimist, but the last 50 years of progress we've seen getting into space just isn't all that inspiring.