Sure, I understand that it's difficult to create the political momentum by turning out the pro-weed vote for Congressional elections, so let's just blame the Prez instead of the law he's enforcing.
The proponents of marijuana are in this predicament because their politicians aren't taking them seriously. If you want to be taken seriously, you need to build a consensus of groups who aren't normally on your side, instead of the under-30 toker crowd. You have to work it in the Red States and not just the Blue ones that passed medical Marijuana laws.
You have to go after the Federal statutes and get them repealed. That's the hard path, sure, but it's also the most effective one.
If you let the other side dictate the narrative about Marijuana, then don't be surprised with the predicament that you're in.
By the way, I oppose these laws for one main reason; they're racist and done more to criminalize minorities than anything else in this country. They even affect and have caused to the deaths of people, mostly minorities, who haven't even had dope in their possession. Even if the President signs an EO, it still won't prevent law enforcement from targeting minorities for whatever reason they deem necessary.
Take the laws off the books, Legalize It.
Anything else is not satisfactory.