Change in America?

Why is assault rifles legal in America? What dumb ass allows assault rifles to be purchased bycitizens without need a purpose to obtain them. In many other countries guns are banned, I am not saying guns need to be banned but I am saying why can't there be strict gun laws, like having to state why you need a gun. Even if this law was implemented no right minded person would need an assault rifle. Bump stocks are not even illegal and now they are trying to legalize silencers!!! I like guns but like really?