I've expressed the same issue with regards to fedreal marijuana laws. I'm in favor of marijuana being legalized. I think that the amount we spend on stopping people from doing something like that is RIDICULOUS. That said...it's still federal law right now and I disagree with any president just telling people "don't enforce the law". I think there's a large danger there.
Blue Laws, IE things not enforced for nearly 50+ years and have simply not been taken off the books, is one thing. However, the executive branch simply ignoring the legislative branches laws because it doesn't agree with it on things that were just within the past few years active is a different ball of wax regardless of whose doing it.
In the post I was responding to in the one you quoted me, the individual suggested that the President was okay in doing this because the Congress wouldn't pass the laws he wanted. To me that's problematic because it's basically showing the process and the notion of checks and balances as a sham and further empowers the Executive Branch beyond what it's already been empowered with; basically showing that the attempt to work through the proper process of congress is nothing but a dog and pony show and if the executive doesn't get its way then it'll just do it anyways.