From recent news in India it is heard that bitcoins are used to sell drugs..I know its a currency and it is also used as a normal money... but these can create a bad space in people's mind that bitcoins are used to sell drugs..so they will not use bitcoins... Conclusion is that BTC is also a currency which is having a high value in the market..and bitcoins must not be used in these illegal activity which can reduce its usage and value.
I think they are too negative to say that bitcoin is just illegal activity, but many people use bitcoin as a big profit investment, many people choose bitcoin because of its safety and its benefits, and that says bitcoin for illegal activity is those who do not like bitcoin.