Indeed, the question of the bad EU regulations has been raised regularly and whenever an answer is given it invariably turns out to be a partial or complete lie. Boris Johnson recently waved a kipper around declaring that EU regulations forced UK producers to ship them with an ice pack. This was simply untrue, the regulation in question was a UK regulation.
In other cases, such as bendy bananas or not being able to sell bananas singly (or in too large bunches, the story changes), it turns out to be a wilful misinterpretation of the relevant EU legislation.
At least one of the claims that regularly crops up (not being able to call British sausages, sausages because of their low meat content - instead they have to be called offal tubes) comes directly from a comedy series.
The UK has voted in favour of 98% or so of EU legislation and has an opt out for the important parts of the remaining 2%. Any international relationship is going to involve both parties accepting some terms they are less than thrilled with. If the UK thinks that the EU has been unfair, wait until we see the terms of the US/UK trade deal.
Ultimately it all goes back to cowardly UK governments of all kinds blaming unpopular legislation on the EU (whether or not they had anything to do with it) and claiming credit for popular EU legislation for 40+ years. That kind of propaganda is likely to leave a very biased impression of the EU.