Eh, the D'ni (I'm not sure when the Ronay got it, or how much the other breakaway groups did with it, other than the Terahnee, and whether or not it would have to be given to the Ronay for the D'ni to survive and escape) didn't do too poorly with it, given that they made a somewhat stable civilization around the Art for thousands of years, tried to rule well at least part of the time of that, in some ways, and at least managed to keep the power from being too much a tool of destruction for most of the time (although they didn't manage to keep it from being used to enslave a lot of the time - other races could have been worse at this). They were at least a somewhat slow, solid, and dependable race, which managed to stay safe and build up records and stuff so the Art never got totally removed, while not ruining too many other races and Ages.
We haven't really seen many better options, I'm afraid, in the Myst universe. Humans - well, we have enough records to see what we'd do with it. Then we've seen the Narayani, who lived in an unstable world, even with all their care, and fell into civil war and neglect that almost destroyed them entirely (yes, it was prompted by outside influences, but it wasn't entirely due to that). The Rivenese were broken into splinter groups of superstitious people, including some who were happy with terrifying the rest of the population for a rather futile rebellious action against Gehn, so it wouldn't suggest they are somehow better or great at using resources either. The bahro - eh, there's another civil war and sneaky dealings, and they arguably already have the Art (or wouldn't really be made more powerful with it).
Clearly, the Art should have been given to the Eder Kemo keanulints. They are always patient, even though they've probably been there as long as the D'ni, and has anyone ever seen them be greedy or warlike? Plus, they could really use the added mobility, apparently.