All music tends to sound the same to those it doesn't particularly appeal to - any music.
I'd have retired at forty if I'd been given a £ for every time somebody said - all folksongs sound the same, or all classical music, or all jazz, or blues.... or whatever type of music happens to appeal to me.
I'd never heard Gillian Welch and David Rawlings, until I just searched out one of their tracks - almost exactly the same as all those country duos I walked away from when I was twenty (except slower and drearier).
One of the features of music that turns you on is that you tend to listen to it closely and discriminate - a cross we all bear!!
I really don't think that applies to pop music to the same extent, which has to be rem-marketed and re-wrapped periodically by the industry in order to be profitable.
Today's flavour-of-the-month will "all sound the same" in a few years time.
Jim Carroll