Everything new and revolutionary that exploded into the mainstream was used by criminals only at the begining. Wireless communications, internet, encryption... it all ends up used by the mainstream, BTC will be no different.
Exactly. Bitcoin has several useful aspects. That those aspects are also useful for criminals is no wonder - hell, I bet they also eat and drink. Criminals simply always have an incentive to "stay ahead of the curve" in order to have an advantage over law enforcement, etc.