American only fits 10 of those seats in the same space that JetBlue fits in 16 of its Mint seats which are the Thompson Vantage. I don't think the Webber Cirrus reverse herringbone seat is a good use of space in a narrowbody configuration. The aisle is far wider than necessary.
To be fair, though, those 6 'additional' seats, do not satisfy the 'direct aisle access' part of the equation, as set by MAS.
Thus, the AA configuration better suits their demand -
The A321's Cabin Width is 3.70 m (12ft 2in) https://en.wikipedia.org/wiki/Airbus_A320_family#Specifications
The 737's Cabin Width is 3.54 m (11ft 7in) https://en.wikipedia.org/wiki/Boeing_737_Next_Generation#Specifications
So, even if the seat design were unchanged (and remained constant in dimension); the subtraction of space would be necessitated from the aisle;
146" (A321) - 139" (737) = 7" of aisle space less.
Thus, it would also satisfy your issue as well;
The aisle is far wider than necessary.
I agree with your premise, though, that a removal of the 'direct aisle access' would yield a more productive/efficient use of space within the cabin. Who would know, better than MAS, as to what their customers require/desire/are willing to pay for.
AA's example is much more geared towards single, business passengers. B6's examples (especially the non-direct aisle access) could be marketed towards couples traveling together, but would also almost naturally mean that those non-direct aisle seats suffer lesser demand/command of a premium yield.
I could logically see:
The MH international network has a lot of 4-6 hour overnight flights. They aren't full long haul overnight flights but many have 11pm-2am departures. There are comparatively few flights in Europe departing at that time.
that MAS saw the potential for profit, to be greater with the configuration more broadly being centered around the idea/design of sleep (and not being disturbed by a neighbor - in the pursuit of profit).
So, while perhaps not the most efficient, I applaud MAS's vision here, and hope that they not only do well, but that we see more daring, beautiful and discerning premium cabins on narrow-bodies going forward. Here's to hoping that MAS does well!