I have worked with Unity since their debut to Windows with 2.0; before that it was a Mac only game engine.
I know exactly what I am saying; most kids choose between Unity and Game Maker to learn game development and publish their first app to mobile stores. It’s the majority of Unity users.
Only for the version 3 to 4 some serious studios began to use Unity for production. In the “pro field” almost everyone has their minds made up about Unity: it’s a mobile game engine.