My irritation comes from that decision/realization happening after we already devoted engineering time to something--the most expensive time to reverse yourself.
I've hit this many times over the last 20+ years, and have come to recognize/accept that most people can not really grok something until they can 'use' it in some capacity, often with 'real' data.
Clickable wireframes, design sessions, mockups, etc - they can all help explore ideas before code, and potentially save things. I've had numerous examples where I can identify "this is confusing" or "this doesn't solve the problem, just moves it around a bit" and I'm usually 'outvoted' by others, and do the work. It's usually only after it's in peoples' hands that they identify the rough edges (or more).
100% agree; I'm a huge fan of the design and product process. In particularly I feel like every product team needs a designer--probably not dedicated, but like, dedicated designer hours. It's yet another case of "1 hour (of design) upfront saves 20 engineer hours further on". I've had the (mis?)fortune of working on teams with and without designers and the difference is super obvious, at least to me anyway.
Years ago we had an open session for how to display some unintuitive data on one of our websites, and while few outside the dev team participated, theirs combined with devs' ideas resulted in around 5-10 totally different designs. Mine was one of the first eliminated, most people thought it was weird and confusing. Four months later, after developing and putting the two top-voted ones in front of users and finding they still didn't understand it, our designer came up with basically what I originally suggested, with a few tweaks to make it look nicer. We've kept that version since then.
Clickable wireframes, design sessions, mockups, etc - they can all help explore ideas before code, and potentially save things. I've had numerous examples where I can identify "this is confusing" or "this doesn't solve the problem, just moves it around a bit" and I'm usually 'outvoted' by others, and do the work. It's usually only after it's in peoples' hands that they identify the rough edges (or more).