There would have been no website to sign up. You ever use a website to get your SSN? I didn't. When my mother had to claim her SS and Medicare benefits the already up and running structures in place, though a bit rough around the edges, worked fine. Why it was thought it would be better to make up a brand new system, process and bureaucracy to implement something that is already working and already scaleable.
It was clearly a bad idea and this whole thing makes the opposition look like they were right all along which of course they were, even if for the wrong reasons. Yes the ADA ought to be done away with but not for the status quo. The ACA is a poor excuse for handing insurance companies more customers. And a lot of people are finding out I and others were absolutely right to point out that said companies will make more money because they have every right to charge more to meet the new "floor" of coverage that is legally required (the reason why so many are getting cancellations in the first place).
I'm certain that this will be rectified in the near future with modifications, deadline extensions and the like. And the insurance companies are about to make a nice bit of change even with the so called increase caps. All in all, all of this would have been better with single payer.