website works--will the policy?

As republicans have claimed that its not the just the website but the real problem is the policy. Why? There was a reason why certain people were not able to covered because certain conditions cost more money.The issue of pre-existing conditions should have been resolved under a separate funding mechanism.  The people who need to sign up to offset those who will need to use insurance are not likely to sign up.  This means that the people who need to sign to make the exchange financially viable wont.  Also there are young people who will just sign up on their parents plan who are 26 and under.  Also many who already have insurance through private market are being cancelled because it does not meet individual mandate requirements.  Now you have the potiential of more people being uninsured after the law than before the law. Also many insurance companies in the exchange are limmited their network of coverage so that you may be required to switch doctors who may now be out of network.  Also the premiums may be low for some but the deductibles are sometimes double or triple.