Hoping that an explanation might smooth the waters as it did for me after I was told the story.
The main issue is memory caching and memory management. Not a huge issue with linear or tabular data. But throw in all sizes of object data, then it is down to the language and the platform. Yes some OS's manage memory better than others as well. If you've been around that long then you'll have noticed things getting faster and more stable with fewer memory issues. The more refined QT gets as it ages, the better off things will be.
My remote server runs on Linux and I've really experienced many positive changes over the years.
Have fun with it, margin is getting better all the time!
CTShaman