In this country, once a law is passed by Congress and signed by the President, there are only two ways it can be changed or repealed:
1. It can be declared unconstitutional by the judicial system (the Supreme Court being final authority).
2. Congress can change or repeal the law via the legislative process.
There is no choice "3", despite what the actions of the Speaker of the House* and his leadership team would have you believe. Yes, that is correct, "shut down the government until the law is gutted" is not one of the ways laws are changed in this country.
If the Affordable Care Act is such an abomination, then the Tea Party should work to win the Presidency in 2016, hold the House of Representatives in Tea Party hands, and gain control of the Senate. They can then repeal the law. Period. Note that they tried the judicial route and failed.
This whole sad episode sets a dangerous precedent for our country, creating an extra-legislative process for governance that is simply wrong. Let's hope sane-minded individuals from both political parties work towards ending this shut-down, change the Affordable Care Act for the better (via the legislative process), and stop kowtowing to the extreme fringes of American political discourse.
(*) For the record, I don't think that the Speaker actually believes what the House is doing is in any way correct. However, I think he desire to remain Speaker is stronger than his desire to exercise common sense.