They can't stop Bitcoin but they will influence how people use it. 

The Bitcoin network relies on businesses for it's infrastructure, users rely on mining pools, LSPs, custodians... All regiter businesses who will follow the laws and regulations, and so will their customers. 

 Once a year you dox your Bitcoin transactions to the IRS, your accountant, and an accounting software company. Why? Legislation.

Don't you think that the reporting obligation doesn't change how some people use bitcoin?