One aspect that seems to have been overlooked in this thread so far is that each and every wanabee is in a different situation from the next one. In other words, some can afford to wait (they may be younger), some can't (they may be on the wrong side of 35 and have a new house/wife/young kids/a mortgage etc.) and by the time the airlines have been forced to change their approach to type ratings (no doubt they will only do so slow and reluctantly), these guys/gals feel (rightly or not) that they will be past their sell by date (most airlines having a moving scale of age vs. experience these days). Some have contacts within the airline industry (hopefully the right ones), some don't and feel that the only way to get on the first rung of the ladder is to get the rating; some have the spare cash or are willing to borrow yet again, some don't (or won't).
Remember that if you ask someone on the Continent how much it costs to get from zero to flight deck, they will probably answer something in the order of £75,000, since they include the price of a rating. The reason? Bonds ARE illegal there, so the airlines won't even answer them unless they have a rating...
Also, why should a regional/cargo operator be willing to fork out the price of a TR when they know damn well that they are at the start of the food chain and that most of their pilots will have left for pastures anew within a few years' time?
True, nobody should have to pay for a heavy jet type rating at their expense (and certainly not without the promise of a job thereafter), but some guys/gals I work with have done precisely that and walked into a job with a well-know low-cost operator (not FR) right after it. They probably think (rightly, in my opinion) that it WAS money well spent...
Cheers