From my perspective (as a Brit) it's us that have been the petulant ones, demanding special treatment and opt-outs from this directive or that, then throwing a temper tantrum when we couldn't have our own way.
All of that, combined with a relentless decades-long campaign of lies and vitriol from the Murdoch press, resulting in such gems as "the EU demands we have straight bananas!" among various myths, falsehoods and outright lies about the EU;
http://blogs.ec.europa.eu/ECintheUK/euromyths-a-z-index/
The entire leave campaign has been fuelled by an outrageous sense of entitlement on the part of a huge swathe of the population that cannot accept that we are no longer a world power to be reckoned with, and the hilariously inaccurate perceptions people have of the various EU bodies and how they work.
The EU is far from perfect, but by comparison the UK is a fucking catastrophe of systemic classism, crony capitalism and unelected hereditary privilege.
How would you describe the EU's actions right now? Rather than firing Junker and reforming, they're going to try and punish the UK to try and frighten their own citizens into staying EU members.
That's not rational or a considered response, that's an emotional one at odds with what is best for all of Europe's citizens.