[overgard]

I can't speak for the grandparent, but using C# in Unity, the garbage collector is always at the front of mind and dissuades people from using some of the nicer features of C# (LINQ, etc.). Granted my knowledge of this is a couple years old, so maybe the situation has improved, but I'm guessing most Unity developers are still very careful about how they write loops and how/when objects are allocated and all that stuff. Automatic memory management can be more of a hindrance than a benefit if you have to babysit it to avoid GC pauses.