If you plot out all usage globally, recreational use is probably going to be the most common case. However, being recreational is not a property of the substance itself, so the term you both were using is misleading in that sense.
Are you under the impression that a substances effects are somehow mediated by their legality?
Not at all. I just realize that these are primarily used for recreation. It could change - I mean, look at cocaine - and it can be both (opiates, for example).
Fair enough.
Cocaine is both too, by the way, stops intra-nasal bleeding post-op.