It's because most people don't take 45+ minutes so they don't know the difference. In 10-20min you just have soft brown onions... but once you truly caramelize, you know it's totally different.
I would assume professional chefs (who are the contestants on these cooking shows I watch) would know better.
I swear, it feels like an onion conspiracy.
Call them what they are...
(To be honest, for many applications, I would slightly prefer sweated onions over caramelized onions.... I'd just like to know what I'm getting...)
... Unless there was an onion conspiracy...