I wonder who in this comunity has ever claimed that the blackmarkets is our (Bitcoin's) goal. It is simply a nonsense assumption.
This, 100 times this.
doesn't matter if anyone claims its the goal of bitcoin or not, the fact is that bitcoin is the money of choice on internet black markets.
It is the currency of choice because it is the only currency that can be used in the same way that cash can be used over the internet.
This argument is very similar to saying that cash is the currency of choice for drug dealers (on the street)