How much of this is simply because of hobby-level or inexperienced builders, though?
When I was a full time EE, answers to questions like this were just a phone call away. The part manufacturer's FAE (Field Applications Engineer) were happy to answer questions like that ("what's a cheap, low-dropout 3.3V regulator that can handle 100mA and won't be on allocation anytime soon?") and would be around the next day with samples.
Even for our tiny company, we got excellent service. Hell, I had FAE's visiting me when I was working out of my apartment! Has that changed these days?