England and Scotland (as well as Wales and Northern Ireland) are very clearly a partnership. There is significant imbalance therein, but that doesn't render it nonexistent.

And the UK is very much flapping about with little idea of what it is doing and why. Immigration does seem to be the biggest concern - but there is little evidence as to why it is the biggest concern.

If anything, I'd suggest that Brexit is the result of the same phenomenon that elected Trump - a general dissatisfaction with the state of governance and a lack of options with which to deal with it. People are understandably frustrated and want to effect some change; it's easy to believe promises made to this effect.