1. Non C++ devs don’t want to write C++/participate in the C++ ecosystem at all. While there are plenty of QT binding libraries for other languages, they seem to be of varying and unpredictable quality.
2. QT has potentially difficult licensing: https://www.qt.io/licensing/
Disclaimer: I’ve never used QT.
However, the library components offered under LGPL3 are all you need to ship a perfectly good desktop app. The GPL3 licensed stuff listed in the comparison chart on the page you linked are typically the utility applications like Qt Designer which you won't need to ship with your application anyway.
It's unfortunate how the company backing Qt is going about this. But it's a great framework overall.
(At my last firm, we shipped several apps via Qt and it's always been a joy to use.)