Presidents delegate authority to people carrying out their policies. In the end, the president is held accountable for every decision they make whether or not they actually personally implemented it. The ACA is the Obama administration signature legislation and policy. This is far more than technical issues, it is a bad law. A lot of Democrats are worrying about keeping their jobs next November. As witnessed by Bill Clinton telling Obama to keep his promise and Chuck Todd's report on how Democrats in the house and senate are privately going to the president and telling him they want to be able to change it. And yes, he lied, which is at the root of why the ACA is blowing up in his face. We'll see if he has this site up and running in 2 weeks like he said he would.