You got the right explanation. It is a thing and you cant blame it. It will not react to everything you file against it. The one who used it will be the one who will be liable for the act that he or she did. Simple as that. Every currency can be used even the one with a low value.
So if you are thinking to use bitcoins for your illegal acts it is better if you are just going to keep away from those type of transactions.
Because it is really hard to live behind the bars as I know a lot of people who did some illegal transactions and they caught, even it is not in bitcoins.
But with the law of cyber, there is no law if you are going to use bitcoin for illegal activities.