I also think the possibility to delegate RCs (rather than sell it, or maybe both, since they regenerate) was intended from the beginning.

I remember a cryptic post of @ned from some time ago, with only three words in it #bandwidth-delegation-pools, and I think that's what he was hinting about.

I saw a few vehement reactions against such a possibility, considering Steem is complicated enough already. But I don't think anyone is forced to use such an added possibility, things can be kept less complicated and still use the DApps. Many use them to post, comment and vote without knowing much of anything else (or caring about it).

Personally, after the 10x adjustment, I have way too much unused RCs. Almost always at 100%, pretty much the same way as the bandwidth was before. I really don't need so much for my own account. Others do, but they might not want or have the resources to power up enough for their RCs needs. So a market for RCs seems logical to me.