which means we'd better stop dismissing lunar and asteroid mining and such as sci-fi dreams and start figuring out how to make them work
Well then start there, not build the Enterprise and say "When we're ready to build the warp drive..." because even Mars One got more realistic plans for travelling to Mars than anyone got for lunar/asteroid mining.
your workforce for the next step can have a place to stay in orbit rather than commuting to and from the surface all the time.
The effects of radiation and zero-g, not to mention humane working conditions means you'd want to rotate the crew a couple times a year. Nobody will live in space any more than they'd live on a nuclear submarine, unless it's another massively shielded artificial gravity sci-fi dream.
And ultimately it'll end up being recycled into raw materials or basic parts for something else once it's no longer needed
Nobody has such plans for the ISS, if you don't want to spend $3 billion/year to keep it in orbit all the plans I've heard for it is to deorbit it into the Pacific.
No, it's not going to be easy or simple. Colonizing North America wasn't easy or simple either, but we did it.
Who we? The 15th+ century colonists who managed to settle in a land already inhabited by Native Americans in the south to Inuits in the north? You're talking about living in an area where humans have lived since long before we had any kind of civilization or technology. It doesn't even remotely compare to the hostility of space.
Though I'll admit that attitude does seem kind of insane to the couch potatoes. Not really my problem though, my entire career my motto's been "They don't pay me to not get the job done." and the older I get the less reason I see to change it.
But on a wild bet I'd say it's not NASA paying you... if I'm an armchair naysayer, you're an armchair quarterback. And if you worked for Ford, we'd all be travelling around in flying cars by now.