Currently, the majority of BTC owners are investors. If it becomes mainstream, then maybe change it, but for now the classification is correct.
The problem is, Bitcoin will never become mainstream and function as a currency if this regulation stands. The chicken just ate the egg.
If you keep your money in an interest-bearing account, the bank will send you a form that it files with the IRS showing the profits you made for the tax year. For most people, this isn't a lot of money and they pay their taxes on it.
Since one of the mottos of bitcoin is "be your own bank", it becomes your job to track your own capital gains for the IRS. Software is available to do this, so you don't need to do it manually. At the end of the tax year, it prints you a form showing your gains. Keep the documentation in your records, report it on your tax return. Boom. done.
Whats the big problem?