Mate, you are so focussed on the 'majors' you forget there is another world out there operating RPT jets. Just off the top of my head: Alliance, Network, Air North, Cobham, QLink, JetGo, not to mention the corporate bizjets, overseas job prospects (some, like Air Niugini even offer Aus base), top tier GA positions etc that are all open to the person who has had a well-rounded career.
This industry has ups and downs, and when it is down, the GA guy will have more freedom to move and options every time - hands down.
Maybe you're the one with the tall poppy syndrome feeling insecure about your prospects?!
I'll shut up now as it's not really my barrow to push anyway as I actually never wanted a major airline job. I'm not bitter and twisted. It was never on the career goal radar in the first place. You wouldn't understand I guess...