OK, buckle in. Saint John sees the suburbs as parasites, using the city for work and play but contributing nothing for the roads and services they use. Counterpoint: commercial/industrial tax rate, shared facilities commissions.
The KV (colloquially, Rothesay and Quispamsis only, but technically everything from Millidgeville up past Sussex on both banks could be the KV) sees SJ as the poorly-managed authors of their own misfortune (points, laughs at every mayor since Elsie Wayne).
Residents chose KV for some combination of larger yards, cheaper taxes, less fog, a more "country" feeling (pre-98), living in one's hometown (post-98), and newer schools. Those reasons could themselves be a thread. Point is, KV doesn't want to be governed by SJ's management.