Hopefully, informed people. Unfortunately I don't have a definite answer to your question but that does not make "the market" a valid one (maybe it is, though I don't think so because I don't trust people for making decision virtuous for the community through individual ones, there needs to be something more clever and functional).
Well I ask because in my mind it is simple: individuals decide for themselves what is virtuous.
Of course as a side effect this is reflected in the market, as individuals engaging in things they find virtuous are reflected in the market.
If you don't trust people to make decisions for the community, why not just let them all make decisions for themselves and nobody else? That would solve that problem, no?