It is because of habits. Oh, you are so flexible and have wide ranging know how. Not really, you have habits, preferences, comfort zones, patterns, familiarity, a groove, work flows that fit and name brand loyalty. So when change comes along it hurts, adjustments need be made, seems whacked, strange, I'm risking something here, there's a learning curve, it's new, it's different, I've gotta get use to this............
The antidote to computer anxiety has always been good instruction and play time. You learn the basics, accomplish something simple and mess around a little. You begin to build appreciation by figuring out how to do the things you've always done. While you are doing all this you see how the system responds to your input and how to maneuver the screens. Knowing what to expect is a big part of comfort.
I've been a big fan of the Gnome desktop in Linux many years, been my first choice because I understand how it works as a user. KDE always seemed like one extra step to do the same thing. In the past the computer world acted like sugar junkies. The eye-candy in full explosion mode after bootup. You couldn't even see what the heck you're doing for all the whiz bang. It became the selling point or the bragging rights, "ooh, lookie what I can do on this!" You can still have this but now it is hidden behind a control panel. You can tweak to full bloom if you want to or not. So you can see what kept me and KDE apart. Today, I am pleased with a modest amount of glitz. I don't use my computer for showing off, and need that power to do useful stuff. OK, I show off a little.
KDE so far is snappy, some applications open faster than in Gnome. KDE and Gnome are not polished in the same places. Gnome has nicer window trims. I'm trying to do what I've always done, which makes KDE seem awkward. The feel is different. Confidence comes with experience and time. Now, I've got to go so you folks keep on doing what you do and also try something new.