4.Bitcoin is used for illicit activity.
This has been in the front of criticism of bitcoin by most people especially those in government which is one reason they give for not adopting bitcoin into their constitution a a means of payment just as fiat. This though has not stopped the use of bitcoin by large majority, the use of bitcoin has increased from it early stage.
That's right. We don't really have to go to the government because basically, even ordinary people thinks that way — bitcoin is a scam and is just an instrument for fraudulent activities.
That's primarily what comes to their minds even just hearing the word "bitcoin". Other criticisms come next when someone is finally in this field and uses it.