I believe I can say with some authority that a 737 or A320 simulator is NOT anywhere near to the "best" way to learn to fly airplanes. While the MPL may be an expedient way for 3rd-world airlines to find co-pilots to fill their seats, I do not believe it is a "good" way to train proficient pilots.
You may have a point. I am inclined to disagree, but I believe that aspect, rather than the contrary point of the value (or not) of seat of the pants solo light aircraft flying, is the real issue at hand.
As I said before, ZFT exists, and works for experienced crew TRs. An effective programme may mitigate those concerns, but unless one works with MPLs, it is conjecture to suggest their quality of experience is better or worse.