Yes - this is a serious problem, one that is mentioned periodically. What's important in this case is to consider the potential solutions to the 2-party system. Strategic voting in smaller districts can help. Libertarians have shown how this can work, but they are also famous for not legislating once they get a seat. They're not only useless, they help the Republicans by agreeing with everything they want. It's a ridicuoous party. At the national level, votes will only matter for candidates who are electectable. At the local level, there are 3rd party candidates who can win elections.