Let's apply this metaphor to programmers working on UIs: a huge chunk of practitioners right now get by via simply having learned a bit of CAD (i.e. HTML/CSS/JS). And also, yeah, they have walked over a bridge once/seen a panoramic postcard, so there's that. Very ad-hoc, very disorganized, full of gaps.
Of course the impact of mistakes is magnitudes different between designing bridges and building UIs. Except for when that UI drives medical automation. Or finance (one of my faves is an anecdote about how a bad input form field cost a fund management company literally in the 8 digits of money).
Our industry is of course very young, and so I think this education gap is simply a temporary issue. I am looking forward to (and am personally investing into) a day when there will be a more systematic and comprehensive education on how what a good UI looks, behaves and feels like, not just how to code buttons and boxes on a screen.