There was no indication that any of the farmers interviewed voted for brexit. In my community very few did, and whilst many are now sanguine, some remain furious at the result.
My own impression of the article was that it reflected poor government policy as much as it did the issues of selling into the EU post-brexit - the failure to get the replacement for the CAP into place quickly, and with sufficient information to farmers, and the potentially alarming giveaways in the antipodean trade deals.
The CAP, the EU's biggest budget item, is itself, in my view, a piece of work. As the article also clearly pointed out, it massively advantages big, probably already wealthy landowners. I would add that it is also shockingly environmentally destructive, and has proven liable to sometimes considerable amounts of corruption, most notoriously in Hungary and other eastern EU countries, and traditionally, Italy. In the UK most of the biggest beneficiaries of area payments could manage quite comfortably without them, whilst those who benefit the least - small-scale and hill farmers most obviously - should have more support available to them.