The problem is, such decisions are taken in the beginning of the project when you are far from full picture. Then comes rest of the app lifecycle - decade(s) of changes, bugfixes, replatformings, data/os/cluster migrations and so on.
I've seen, and even currently work on stuff that has beautiful but hard-to-grok abstractions all over the place (typical result of work of unsupervised brilliant juniors, technical debt in gigatons down the line but its almost always other people's problem). The thing is, that code has seen 10 major projects, absorbed other stuff, meaning and structure of data changed few times, other systems kept evolving etc.
Now all those abstractions are proper hell to navigate and perform any meaningful change. Of course another typical brilliant 5-second-attention-span junior result is complete lack of documentation. So you see stuff happening, but no idea why or why not, what does it mean down the line in other systems, why such choices were made and so on.
These days, I've had enough of any-design-patterns-at-all-costs kool aid and over-engineered cathedrals for rather trivial stuff (I think its mostly down to the anxious ego issue but thats for another discussion), I am more than happy to copy&paste stuff even 20x - if it makes sense at that place. And it does surprisingly often. Yes its very uncool and I won't brag about it on my next job interview, but it keeps things refreshingly and boringly stable and surprisingly also easier to change and test consequences, and somehow that's the priority #1 for most of the companies.