TNG never explained how Padds worked either. Doesn't make them "magic".
I dont think you have to explain everything, as by definition, a lot of the things we see will be basically impossible to replicate at this point. However, there is a big difference between something like the tricorders and the kind of magic we see on game of thrones.
One is an extension of science as we know it, to encompass a logical need in the future and the other is a need humanity has always had, covered by an inexplicable plot device.
I dont like magic because it not only doesnt follow our rules, but its doesnt really relate to them at all. Furthermore, it seems to show scant reason in the world we are being introduced to. In game of thrones there are magical assassins who can kill anyone. Well thats great, but surely that would destroy the concept of security and completely dominate wars. Also we have smoke monsters killing kings. Well it happens once, - why not more?
In the ST universe there are elements that appear to be magic, but they are usually encased in episodic drama, that compartmentalises them into neat meetings with new cultures. What we dont usually see is stock characters and races such as the klingons and ferengi using magic, because it would mess up the substantive texture of the show. In things like GOT, there is far more "magic" mixed into the texture of the show.
But in any fantasy setting, the magic elements are part of that world. Is it any less unrealistic to have explicit magic than the completely fantastical 'science' that ST uses in its everyday storytelling?
If you are using Star Wars and the 'force' as an example of magic in a sci fi setting, how is this different from Kes and her powers? Now you can argue that most of the telepaths are aliens: Vulcans, Betazoids, etc but practically the first ever magical powers we see are Charlie Evans who was 'bestowed' human.