Ye well, count me under those. I am using it since version 2. Many of those veterans are still beginners actually, other than fiddling around with a bit of C# and the engine for some years.
The pricing model surely is bogus, for my situation at least, but that does not diminish the engine and its capabilities itself.
I prefer Unreal in a lot of ways to Unity, but the thing that makes me stick to Unity for some projects is the fact that it feels more stable in many scenarios and code iteration can be lot faster.
In my day job I use both C# and C++ so that is not a compelling enough argument to disregard either engine, no professional programmer would actually.
Your argument earlier was that Unity makes it so easy it draws you away from knowledge. But the exact opposite argument can also be made; Unity actually misses a good set of tools that Unreal does have.
Those tools you would have to create yourself in Unity, thus gaining valuable knowledge. In Unreal you already have them, no knowledge gained.
Concerning Ogre etc; many companies actually prefer in-depth knowledge of either Unity or UE4 rather than a framework such as Ogre. Being a competent programmer is a requirement for pretty much all, you don’t need Ogre for that.
Dropping either engine in a heartbeat should skillset and project requirements. I can drop Unity in one project and decide Unreal is totally useless in the other, for example.