I would dispute the 'relatively accurate' assumption. My father works in construction and it's often the case that what me (as a non-construction worker) sees as a beautiful kitchen, he'll see as a nice-looking kitchen that's been cheaply made with quality and craftsmanship problems.
I would imagine that a bricklayer has a better chance of telling you whether a wall is likely to start cracking within five years than your average person off the street would, for example. You're assuming that non-bricklayers would know what to look for to assess the quality of the wall properly or that brick walls are so simple that any untrained person off the street could figure out what all those hidden factors are.
I think this is actually the exact same thinking mistake that people make when they assume that programming must be easy. It's seeing only what's on the surface and not realising there are deeper things (a previous poster mentioned 'hidden processes' when talking about laying down a hardwood floor, which is exactly what I mean here).