Acknowledged, but even if I was sufficiently tough and motivated to be an ice rampie for several months or years, I'd be worried about skill loss and asking myself about the point if
all I get to do has little to nothing to do with actual flying. Thoroughly testing for cultural fit, eliminating any skygod attitude etc. is all cool and pro, but there is IMHO some latitude between immediately complimenting a potential new hire into the cockpit and keeping him/her out of it for several months or years to check his preparedness to accept ground duties. And referring to a previous post*), I certainly doubt that months of ramp work are any effective prevention of further "37,000 ft plunges".
Anyway, one must probably not forget that what one gets to see is a TV show. The reality might not be quite as black & white (and full of uncompromising starting-from-scratch-and-remaining-there-for-months-or-years romanticism), so actually new hires may get to log some flying time
in addition to doing a fair share of ramp work :-?
*) http://www.pprune.org/interviews-jobs-sponsorship/495961-humiliation-canada.html#post742371