And who would screen candidates? The FAA, the airlines, ALPA/professional pilots? I'd bet each group would vote for themselves as being the most qualified to do so.

Exactly the 'need' for the MCL. As flight training costs decreased in the US over the past decade, the supply of potential new professional pilots around the world increased, and correspondingly, the need to entice new entrants into the flightdeck decreased (wages). Now that training is getting more expensive and the credit markets have dried up, the barriers to entry are high. Right now, there is no demand for new pilots (excess amount already in the system, coupled with furloughs, and then the 5 year increase in flying careers is the perfect storm). There will likely be fewer new pilots over the next decade, meaning demand to entice new entrants into the flightdeck will rebound when discretionary income rises and the glut of current pilots abates. Both seem on track to occur around the same time, 2012.

The MCL fixes this, lowering barriers to entry again. The glut of pilots continues, supply outpaces demand, and both current and future pilots see compensation and QOL continue to go downhill until this profession becomes so undesirable that even practically giving it away (the MCL) isn't enough to entice new entrants into the field. In short, there's a LONG way still to go to reach this point.

There is currently no need for the MCL anywhere in the world. If you need a pilot, anywhere in the world, there are literally thousands of currently qualified aviators just in the US. If you need a pilot to work for less than market conditions, however, you need to find someone willing to work for cheap. Who would do that? Someone who has little value or transferable skills, someone who paid nothing in the first place, someone naive, someone with no debt, someone with the ability to relocate anywhere in the world for a job, someone so unskilled, they can't even command a piston plane by themselves legally . . . someone like a MCL pilot.