I certainly understand your point
And I in advance agree with the examples you are likely going to bring forward proving the cases where the forbidden fruit is the sweetest. But these cases are obviously not applicable to Bitcoin. How come? Because Bitcoin has no value of its own. Right now its value comes from its use as an excellent vehicle for speculation and profiteering. But if it gets universally banned there will be no longer such use, and its utility will return to where it had been when Bitcoin was primarily used as a means of payment in the DarkWeb. How high it will cost in dollars would remain to be seen, but in any case you can safely forget about the first two digits in its price tag as of today
'currency' is magical in that it shape-shifts into anything one wishes it to be. At least within it's sphere of operation. This is completely irrespective of any 'value in it's own right', and indeed, most successful currencies have this 'native usefulness' attribute only to a very limited degree if at all (e.g., gold.)
Put another way, Bitcoin (or any workable 'currency') has the magical ability to turn an illegal drug into and illegal gun which is a very valuable capability indeed.
As a user who can, has, and does use Bitcoin for 'speculation and profiteering', criminalization would suck. For someone who is already a criminal the suckage is much less. Even between these two classes there are areas of overlap. The set of things I am interested in include, for instance, certain kinds of equipment. Say, an airplane. A drug-runner has a different set of interests but an airplane is in many cases one of these. The upshot is that there will always be this overlap between the black market and the mainstream. Bitcoin could easily help in this such transactions due to it's historic acceptance and usability. If not Bitcoin than something else.
In any environment the value of the currency will be largely associated with 'velocity' an 'propensity to hodl' (Satoshi having simplified the currency base part of the equation in the design phase.) The reality of black markets is such that we are probably at a tiny fraction of where Bitcion _could_ be in fiat denominated terms. Bitcoin is eminently 'hodleable' and the value flows within black (or simply non-mainstream) markets are huge.