The EU worked very well for the UK
Isn't there a similar argument along the lines of "Women/minorities should just shut-up and accept lower wages because the system is making us all rich"? An abused wife is going to be poorer outside of the relationship, but that doesn't necessarily mean she shouldn't leave. Iffy analogies perhaps, but bear with me...
There's a tendency amongst the left-wing to prioritise the individual and their rights over the rights of any entity whether it's a country, a company region or whatever. There's a tendency for the right-wing to over-state the importance of national identity. But at the end of the day people are people. They want their identity, be it country/race or whatever and I don't see that changing any time soon, it's just human nature.
The EU, meanwhile has this strange mix of the two, where they allow for instance freedom of movement to some extent, the rights of the individual... to some extent, and yet they have a system for punishing national governments for the (in)actions of the few (e.g. pollution targets) and indirectly individual tax payers. If they get things wrong from an individual's perspective (ECHR judgements) can be considered bad luck, if they get it wrong for a country it could affect large numbers of people in that country, perhaps more psychologically than in real terms.
The EU itself seems to prioritise certain things. It doesn't just sit there impartial letting markets decide. For instance it prioritises keeping food production in the EU. You could make similar arguments about other industries, how they also need to be kept in the EU, but it's funny how this always seems to suit the members with the most voting rights. If these policies disadvantage certain countries (e.g. the ones with small amounts of agricultural land) then it doesn't matter how much money everyone is making. People get a bad taste in their mouths. They *feel* disadvantaged. And it's the feeling that counts here.
FOM is a great example of something suiting industry. It gets you 100s of strawberry pickers when you need them, but if you don't count in the right number of midwives, teachers, doctors, you're going to have some problems. Industry makes $$$, at the expense of health service provision. How do you measure this? Or do you just believe the HS reduction is negligible? Is it just a temporary glitch that you discount completely from any arguments. It isn't negligible if it affected you, I can assure you. In fact it makes your ****ing blood boil. A common argument (usually without any supplied figures) is to just say people are 'scapegoating', another argument (Abbott's favourite, again figures are not her strong point) is to point out migrants are 'propping up the NHS'. You may have seen a couple of migrants working in the NHS, but that doesn't mean anyone is propping up anything. 'Tory cuts' are another favourite, but if you actually check the number of open positions in some of these professions (and I have) you invariably see that the NHS is hiring... or trying to hire... an awful lot of people.
In summary you need an answer to these problems instead of shouting abuse at people for not voting the way you want. If you want to re-join you simply have to do better. It really is that simple. That's why I said I believe we can re-join with the right approach, just not the way we run things now.