The EU is a vicious colonial project completely beholden to neoliberal policies. Case in point: The plundering of Greece, whose government dared try to stand up against the trojka’s privatization regime. Case in point: The secret negotation of and pressure to adopt ACTA. Case in point: The secret negotiation of and pressure to adopt TTIP. Heck, even Infosoc!
Case in point: The extremely shady deal just closed with Turkey, allowing them to deal with the Kurds as they see fit, while excluding refugees whose misery we more or less created ourselves from Europe’s shores.
I admit Britain leaving because of UKIP-style nationalist propaganda is a rather dismal perspective and thus understand the reasons many progressives might favour staying - e.g., following Corbyn’s arguments - but the EU is not in and of itself a laudable project. Even if I do like the open borders.