// Your opinion of it being "damaging" is just that. //
I mean, be fair, it's also the conclusion of almost all studies and predictions about what No Deal would mean for the UK in the short and long term. So it's not exactly an opinion based on mere speculation, but on hard data and serious study.
As to the friends you spoke to, I'm sure that there were a great deal of people who may have just wanted to get out. But there's no evidence that everybody who voted Leave felt the same way, and loads of evidence to show the exact opposite. Besides which, the world doesn't work that way. We cannot but avoid having a negotiated relationship with the EU, be it on economic, security, scientific, travel, political, or on any other sector you care to name.