I think power chords sound better with some tunes.  And, if more than one person is playing rhythm, things seem to work out better if guitarists playing rhythm try to avoid using identical rhythm techniques.  If a guitar is not set up properly, barre chords can be very hard to play, and people will avoid using them.  If a person does more than memorize positions for power chords, and musically understands what they are doing, learning to use power chords adds useful techniques to their playing repertoire.  Play a tune like "Sweet Georgia Brown" using power chords, then play the tune using standard "open" chords.