From the link:
The Mono runtime we use in our Editor and Players has not been upgraded.
The compiler still targets the C# 4 language. This is approximately what our old compiler supported.
The compiler still target the .Net 3.5 framework profile we previously supported.XNA used to sit in this space, and it was a pretty nifty little game development platform for C#. Monogame has carried on, and expanded the target platforms nicely, but hasn't really made many other improvements, from what I've seen, getting back into it after a few years away.
https://feedback.unity3d.com/suggestions/change-font-size-in...
http://forum.unity3d.com/threads/when-will-unity-support-hig...
Second threads ask for support for high DPI. It's a simple scale issue, but somehow hard to do it on Windows.
Stuff that should be easy but isn't is a strong indicator of technical debt.
It can also be an indicator that there is noone working on it. It's common to have fix which are relatively easy but noone to implement them.
Or, they just get their priorities wrong, meaning, they're being stupid. Not a safe assumption in my opinion.
> Or, they just get their priorities wrong
Most open source projects have very few or no people working at all. It's common to find bug reports opened for years that were never fixed. They don't have to be complex, just non-trivial.
Unity isn't just closed source, but your main access to the engine is through an ancient Mono .NET environment that hasn't been updated in years due to licensing issues. The latest re-licensing of Xamarin should help here, but as with many other features Unity will be afraid to make upgrades for fear of braking compatibility.
This means that most of the Unity game code that will set your game apart has to be written in C# 3.0, and your memory use and performance is heavily taxed, unless you resort to platform specific native plugins. As a game developer this scales down your ambition down to mostly casual games. The type of AAA games that Unity advertises are mostly distinguished by large amount of content, but nothing innovative in gameplay or technology besides what the engine provides. I can't imagine anyone starting a No Man's Sky or even a next Minecraft in Unity.
This is sad, because about 5 years ago I was cheering for Unity and having a lot of fun with some prototypes. They know they are a mill for casual clone games too, since they are shifting their business focus to online developer services like advertising and multiplayer hosting with per-player fees.