For what it's worth, FFIII seems to be the most downloaded FF on VC, as of June 21st:
Interesting stats. Thanks!
But that really just backs up my point that whether it was ported or not didn't really matter much in the long run. From the stats you gave, FFIII was still the best-selling title on VC (by a long shot), even after it had just received a substantial remake very recently. The game sold well because people like the game - not because it hadn't been re-released before. As I posited before, if the game had received a GameBoy Color or WonderSwan port in 1999 - do you really think that would have affected the DS sales all that much in 2006?
The stock situation isn't any different than with any multiplatform release.
In this case, it really is different though. With a typical multiplatform strategy, the goal is to sell games to people on a 2nd system who don't own the primary system that you are developing for. You are trying to expand your audience.
In the case of putting PSP games on Vita cards, who is the expanded audience? Honestly, does anyone believe that there are any (in significantly worthwhile numbers) Vita owners in Japan who don't also own a PSP? For all intents and purposes, it seems like the exact same audience. So from the perspective of the 3rd-party publisher, what is being accomplished by a multiplatform release when you reach the exact same audience by just going with a single platform PSP release?
Now where I agree with you is in your suggested Plan B where Sony steps in to make it worthwhile for 3rd-parties. If Sony subsidizes the dual platform strategy for the 3rd-parties, then it's a no-brainer for the 3rd-party. But Sony clearly wasn't interested in adding even more costs to the launch of the Vita platform - so nothing came of the idea.
Looking back, I'm starting to think that it might have actually made sense for Sony to launch with a Vita with a UMD drive built in. It would have been bulkier and less elegant and more expensive, but honestly - could sales really be much worse than they've been up to this point anyway. Up to this point, the only people buying Vita are the die-hards that would have jumped in at pretty much any price and any design (similar to those who jumped on the DS Phat).
That way they have full compatibility for people buying PSP discs, which makes sense given the release schedule (vs. PSP) during the first 12-18 months of Vita's life. Then after 12-18 months, they come out with the Vita Lite (current model of Vita). It's basically an instant relaunch of the system. The new Vita looks remarkably slick and elegant, comes in at a cheaper price (and Sony can now afford to include memory with each system), and hopefully you have a slate of high-quality titles ready to release by now to accompany the relaunch. Who knows, maybe you hit a home run sort of similar to what happened with the DS Lite with Brain Age and NSMB in the vicinity of the relaunch.
Crazy idea, I know.
But looking back in hindsight now, I think that plan might have worked out better than the route that they took.