Courts should go with what the law -- be it the Constitution or the ACA -- actually says, not with what we want it to say, not what we believe is fair, or what we believe the authors meant to say, or even what the authors say they meant to say. Laws are insanely complex enough without adding "well, it says this, but that's not what it means" to it." "Original intent" is a bogus legal philosophy.
Now, I haven't looked up the text of the law. If it's true (as the article claims) that "other portions of the law specifically say that a federal exchange set up for a state is by definition a state exchange" for purposes of the Act, then this doesn't reflect what the law actually says and will certainly be overturned. If that's not true, if there is a gaping hole in the law as written, blame lies with the politicians who wrote it, voted for it, and signed it into law, not with judges who discovered the error and applied it as written.
Two Republican Judges Gut Obamacare, Threatening Health Care For Millions (The Huffington Post)
The two judges seized on text within the law that said subsidies would be provided to people who purchased insurance on exchanges established by the states. But 36 states declined to set up their own exchanges, and chose to rely on the federal government's exchange instead. Because the law doesn't specifically say that people who bought insurance on the federal exchange also get subsidies, the law's opponents argued that therefore such subsidies are illegal.
"The problem confronting the [ACA] is that subsidies also turn on a third attribute of Exchanges: who established them. Under section 36B, subsidies are available only for plans 'enrolled in through an Exchange established by the State under section 1311 of the [ACA],'" the majority opinion ruled, rejecting the counter-argument that other portions of the law specifically say that a federal exchange set up for a state is by definition a state exchange.