I won't comment on the decision because I don't know enough about the law to comment intelligently.
That being said, the consequences of this being upheld by the supreme court would be devastating. This would in effect lead to many more healthy people not joining plans, leading to a sicker pool of patients signing up for ACA plans, leading to higher and higher premiums. While some conservatives who live in their mom's basements and don't interact with the real world will be ecstatic, this decision would unnecessarily hurt a lot of people.
There are a lot of problems with the ACA, and I have outlined some myself and been accused of posting clickbait, but the subsidies are not it. Whoever came up with this challenge is an ideologue whose only concern is defeating Obama, not upholding the constitution or creating better public policy. The ACA is the law of the land and businesses have adjusted to it. There are many ways of making the law better but destroying it creates more uncertainty and hurts the economy.
This. That's why I'm very concerned if the 2014 election shows that the country is pushing to the right way too fast. Beyond the fact that I'm not really for that to begin with. If this decision is upheld, which it probably won't though, I would expect that the ACA will be repealed in full by 2017. The republicans will basically get their "start over" that they want and the Democrats will probably filibuster their counter proposal.