The first failure is adhesion. Kitchen cabinets carry years of cooking grease and hand oil, and a degreaser plus a bonding primer is the difference between a finish that survives and one that peels off a door edge within a year.
The second is cure time. Waterborne finishes are touch-dry in an hour but nowhere near hard for days. Doors rehung too early stick to their frames and mark permanently at the contact points. We cure fronts flat for several days before they go back.
The third is product class. A wall paint is formulated to sit still on a wall, not to take a fingernail every day. A waterborne alkyd or a conversion varnish cures to a genuinely hard film, and that is what a cabinet needs.
None of this is exotic. It is just slower than the schedule most quotes are built around, which is why the cheap version of this job so reliably disappoints.
