well that's because it's not really, the issue appears to be:
#1. Michael used Xrender as opposed to Raster which is the standard and better Qt Backend,
#2. Oxygen and the related GTK themer apparently have some significant overhead issues that other Qt theme engines such as QtCurve don't have..
what interesting is that i cannot feel any difference between xrender and qt backend ahahah
STOP SAYING THAT! Seriously, I'm so tired of that. Have you actually used GS with a touch device? I have, many times, and it's just not usable. W8 is so much better at being touch friendly it's not funny. I'm not trying to be a sick about this only trying to get people to stop spouting something that is just incorrect. Now if you want to say their intention was make it touch optimized you'd haves a stronger case.
The sad thing is that GS isn't optimized for either paradigm... it's just a bit of a mess, but it wouldn't take a huge effort to salvage it.
That's actually what I meant. The intention is that. Since they don't fit me, I don't use them. I only tried them a long time ago.
If it is the default on other distros, when the real question is why are the KDE devs using non-optimized settings?
The default is for GTK apps to use the Oxygen theme, because it blends in with the KDE theme as closely as possible. They could optimize it, but only by making the GTK apps look less like the KDE ones.
They obviously think that KDE users will primarily be using QT apps, and that blending in visually with that is more important than performance for any GTK apps the user might want to run.
The issue doesn't (necessarily) affect Qt/KDE apps - just GTK, so they probably aren't all that concerned about fixing it.
Yeap, as mentioned, Unity is by far not touch-optimised. For instance, you can't use the scrollbars if you use it with a touchscreen. At all. Because the scrollbars are 2 pixels wide and you need to hover your mouse on them to get a scroller widget (good luck hovering with touch!).
You can tap once on thin orange line, the handle appears, then you gan drag it anywhere you want.
or you can simply scroll by dragging the contents with two fingures (or one fingure if you set it up).