So much spin on this here.
It's actually great news for consumers. It allows people to gather into groups to purchase insurance. This was already legal, however was limited in scope. This EO broadens the range so that the groups aren't limited. For instance, health conscience people from across the nation could group together, and purchase insurance. Because they are a large group of health conscience people, they're likely to get a good deal on their insurance. Also, these don't need to follow the ridiculous regulations of the exchanges, so for instance, men will no longer have to pay for coverage they do need because they lack a vagina. At least the conservatives...
LOL at undermine the marketplace. First off, it was doing a great job of failing on its own. The premiums are ridiculous, and the deductible is so high it's not worth using anyway.