"Offer that as an alternative means of payment, perhaps even at a slightly higher price point, for people like myself."

So he's asking to have MMO companies charge him more for his game time?

This idea would effectively put a pay-per-day/hour/minute scheme into place. How much time does he propose $15 a month should cover? I don't see how both models could coexist, They couldn't. If folks see the "time spent" model costing less that will just mean less money in the Dev's pocket and they will either: raise the price of "time spent" model or eliminate it all together.

"Time Spent" is basically another form of RMT, and one that doesn't favor the developers this time. Thats fine for us but would a no-go for them.

I would suggest teh author find a good F2P or item mall MMO.