I state up front that I work on my own terms. I have talent to offer and can solve problems that others often can't, but I place a premium on flexibility and on my own health and family. I am incredibly productive, more than many other employees, but I do not offer *maximum productivity*, i.e. "as much as I am humanly able to produce." Even if it seems that I have more to offer (i.e. I leave at 6:30 when everyone else is still working and Skyping me at 11:30 pm, I travel a only couple of times per year and decline to travel 20 times per year, etc.), I am not willing to give this "more" to the organization—it is for my family and my own personal growth.
And both of the phrases I used are things I've been told—"We have doubts about your how serious you are; we're interested in someone that's more serious about their career" and "We don't doubt that you're highly skilled and productive, your resume and recommendations are stellar, but we're in a competitive industry and we need highly competitive people, and we're not sure you've got that competitive fire in your belly—that you're really going to be one hundred percent invested in the company and its growth."
I have two friends that have been on the serial startup carousel as founders. Both burned out and moved in other directions because they felt it was impossible to actually have a life, be a human being, and get growth and operating capital support from investors. Each startup became their entire lives each time until positive exit, and at some point each said, "I'm not doing this again, I'm losing my own sense of identity and my family."
And if you take that kind of statement out into the public sphere, I'd bet that what others would say is, "Well, they weren't really made to be enterpreneurs, then; they were destined to burn out because it's not the lifestyle for them."
Which is precisely my point—and it sounds like you've seen it, too—there's a prevailing "wisdom" that "real" career builders or "real" enterpreneurs are a particular "type"—the type that gives every . last . drop . of . blood to the company. The rest? They're just not "cut out for it"—they should "do something else."
Of course, if you're not "cut out" for the job market or for enterpreneurship, it's not quite clear what "else" you ought to be doing to earn a living. There are only so many jobs at nonprofits and in government agencies.
It would be better if society were to take a step back and assume the opposite—that everyone is basically loyal, driven, and productive, but in general, a healthy person cannot exist without healthy hours, life balance, and relationships, and if someone is the "type" to be working from 4:00 am until midnight every day of the week, and double that on holidays to pick up the slack, the are probably in need of counseling or personal development, rather than a raise and a promotion. But I suppose that's not how the market works.