I started learning guitar on an acoustic one nearly 2 years back and recently I bought a new electric guitar. I started playing too much of electric distorted stuff, especially the drop d tuning which is quite simple to play, but lately I am wondering whether playing excessively these simple power chords would make it hard for my fingers to play the barre chords, in the long run. Any experienced suggestion is very welcome that suggests to me how to be good at guitar (not only a single genre): what should I emphasize? Barre chords or the power chords?
If you want to be diverse, do more than power chords. Especially if you want to do barre chords, then practice those. Use whatever guitar they are easier on (electric or acoustic) and start from there. I wouldn't hope on an effect from power chords on your barre skills. Most things you do can be positive for other things on the instrument, but if you think you have a need to practice something, or lack skill in a particular area of playing this is very good, because you "just" have to practice on a problem you already identified. Therefore I would focus on the barre chords. The power chords won't be harmful either, as long as it doesn't take up all your time just playing power chords.
Power chords are good fun and especially easy to play with drop D tuning. However (there's always a 'however'), that's about it. Power chords have no gender or niceties. Apart from the songs that use them because of their genres, most other music will feature 7ths, maj.7ths, min.7ths, 9ths, sus. chords, etc. etc., so when you want to start playing most other music, power chords will be the chocolate teapot. Use them for what they're worth, but simultaneously, learn to play - and put them into songs - all the other barre chords that will be useful to you. Simple majors and minors are a good start, and the CAGED idea gives you lots of variety in chord voicings.
Is your problem in just playing barre chords? Or is the problem memorizing barre chords?
You can always play powerchords as barre chords, no problem with that. Actually, doing that, I got a lot better at barre chords. I play most of my powerchords as barre chords. I think you can switch faster between them when you have songs consisting almost of power chords completely (rhythm guitar) also you can mute other strings that way pretty easily, you just have to be more precise when hitting the strings, so that you only hit those strings you want to play.
But I don't think that it is a problem to do both. Why not play one day the electric guitar and rocking with some powerchords and the next day you practice barre and other chords on your acoustic. I think you won't unlearn something unless you quit doing it for several years.
Playing power chords won't hurt, but if you want to be good at barre chords, you also have to practice barre chords, as these are technically harder to get right than power chords.
not only at a single genre
That's a very interesting line in your question.
"Power" chords are very specific to a certain type of sound and are locking you into those genres that use that sound. (Also they're not even real chords in my opinion, but I'll try to keep on topic.)
To be a general guitarist, free of fashions and fads, you need much more. Power chords, barre chords, OPEN chords and many varieties of "jazzy" chords like sevenths, ninths, etc...
(Apologies if the "fashions and fads" line sounds a bit lecturing, but I really think the current Drop-D scene is full of pretty unoriginal players and very few innovators. Studying a wider range is probably seen as "uncool", but you can always do these studies in private...)
just a suggestion; (1) If you are using the e-guitar with extremely hi-gain settings, then you should also logically use/practice power chord structures in this case, as using full or extended chords with this type of setting would only sound like mud (2) Use your acoustic or the e-guitar (with a classic rock / blues type of distortion) to practice the full bar chords. In any case it's just a matter of discipline and practice to get use to forming the bar chord shapes until they become easier and automatic. After you get this far, then it won't matter if you prefer to play one or the other exclusively, without having to worry about neglecting either. Good luck, have fun and rock on...