Greg M said:
That doesn't make one contractor right and the other one wrong as long as what is built is safe and follows any codes that might apply.
Simply meeting code means doing the minimum necessary to avoid jail time and fines.
I spent two and a half excruciating years working for a small woodshop in a large institution. I was the youngest person there by ten years, and the only one on staff that had professionally built cabinets and countertops prior to working for the corporation. Everyone else had a history of building decks or fences or pouring concrete or being related to an administrator, but no woodworking experience. Everyone built cabinets according to folklore based on the work of people who made it up as they went along.
The horror. I saw cabinets built without backs, drawers with particleboard bottoms stapled to the sides from underneath, and white latex primer used instead of edgeband. When edgeband was used, it was cut from sheets of laminate on a table saw, applied to assembled cabinets with contact cement, then flush-trimmed and filed in place. It was not uncommon for work orders for office cabinetry to take six months or more to be completed. In some cases the person that ordered cabinets didn't even work for the corporation anymore. After spending two days building cabinets for an office only to find out the office no longer existed, it became my policy to meet with the person that submitted the work order, just to be sure they still needed what they ordered.
When I would build cabinets the way I was taught, the shop manager would get angry. I shifted my schedule so I would be working after he left, lest he see me utilizing 20th century methods in his woodshop. He chewed me out for dadoing drawer sides and using edgeband. I'd have to do it in secret when he was gone. I learned workarounds for purchasing so I could order the correct materials. It was more like Kelly's Heroes than New Yankee Workshop.
There really aren't certifications or licenses for cabinetmakers here. Any hack that builds a box can call themselves a cabinetmaker, unlike a plumber or electrician. Standards and codes are minimal, where they exist. All you have to stand on is your reputation. So while it might be subjective to say that one way of building a cabinet is wrong, that judgement is probably based on experience and best practices, not a codified definition of what is minimally acceptable.