The only thing I think government will take an impact if they were able to control bitcoin is that imposing tax on earnings that we get surely the government would like to have the majority of bitcoin in the market to sustain their power and to have control over the economy's wealth
You are right, and this thing will be so bad for bitcoin community, because when the governments make some regulation to bitcoin maybe it will affect bitcoin too much. Bitcoin is more good than to be controlled by government, because it will be some rules and bad things..., Futhermore, I see that bitcoin is more better if it will be like that.
let me add that government regulation defeats the purpose of one of bitcoins characteristics which is being decentrelized. Regulation of bitcoin should be upon the bitcoin users, not the government