Part of not making a connection and talking past is refusal to acknowledge the supporters know and understand all that, yet found the alternative to be even worse.
On this side of the pond there's a mindset where people say the US Constitution is not a suicide pact. There is an analogy to EU membership. There's no glory or honor in riding a sinking ship to the bottom. Better to be the first guy out than the last.
And as no one meaningfully important has put forward a plan about what sort of exit Brexit is going to take, that unknown is very uncertain indeed. Long-term things like real estate investment and corporate mergers are on hold, EU students going to British colleges are wondering if they'll be allowed to complete their university education (probably? but still) and vice versa...