Even though the vote was to leave, those in the middle of the EU are still pushing towards federalism, with things like the new defense policy as an example. So there's zero chance that even a close remain vote would have made them think. There's still a desire for it from the key players, they're just waiting for a better opportunity, and a remain vote would have moved them nearer to that.
Many didn't mention the single market as issues that they felt were wrong with the EU, and people such as Corbyn etc were certainly against the existing structure of the EU arguing in favour of changes from within. There are plenty of oter member states that want changes, but they're unable to make them from within.