They detest the differences which used to make Europe such a diverse (in the good sense) and vibrant set of unique nations and cultures. And naturally, the overall bent of that homogenization tends to favor the German model of conformity and Alles muss in ordung sein (there must be order). Many of the regulations ended up causing economic damage as well. British fishermen losing their livelihoods due to Brussels turning their offshore fishing grounds over to others and limiting the British in their own traditional waters is just one example.
Britain in particular has always held itself aloof from how "foreigners" on the continent conduct themselves. And so the arrogance of Brussels combined with what remains of British pride and a memory of their freedoms, the same ones our ancestors saw as their birthright, pushed them to the brink of a polite but firm ballot box rebellion. It's not that dissimilar from Trump's "Drain the Swamp" election, rejecting the heavy hand of D.C., in 2016. In fact the latter probably helped convince the Brits that it was possible for them to put two fingers up to Brussels.
Articles 15 and 17 (formerly 11 and 13) may have been the straw that broke the camel’s back for Remainers.