I think this is pretty important, and we've discussed several times since the start of Monero. If the only thing you can do with Monero is illicit trade, then sellers will just dump it as soon as they get it, in exchange for something they can actually spend. No willingness to hold means no store of value at all. For people to hold money they have to be able to use it for unknown future purchase needs, and that requires wide acceptability and use. You can't live on drugs alone.