...I don't understand British politics. The Conservatives didn't really want Brexit, did they? - or at least the PM didn't want it. But when it narrowly lost, they tossed the towel in and are acting as if a not quite 2% majority decision (in a country with non compulsory voting) is an overwhelming clear endorsement of "leave". Now with a new leader seemingly wanting to be styled Thatcher 2, it's off to an unnecessary election to (seemingly) just rub it into the face of Labour that they've got a useless leader at the moment. (As to how and why he is so poorly regarded - I don't really know.) And as for high profile Conservative Boris Johnson - I don't think he has risen above the poor expectations that most people had of him in the Foreign Secretary role.
Amusingly, I see that one economist writing at The Conversation claims that the election is being held now out of concern for a worsening economic outlook for Britain, yet people in comments were quick to point out that he was only predicting 6 weeks ago that the Budget and economic outlook meant there would not be an early election.
Anyway, the Wikipedia entry on it fills in a bit of detail - including the way the country has swung from one side to the other over the decades about whether it wanted to be in the EU, or not.
I find it hard to believe that all of the energy that needs to be devoted to replacing current arrangements is not going to be a waste of time and effort compared to simply staying in and trying to make bones of contention better.