I agree that difficulty isn't a virtue, and I'm a big fan of minimal art and music, but I don't think 1-4-5 power chord music is the pinnacle of musical achievement. But I think those simple songs were extremely powerful in their cultural context and the rejection of norms that they represented.
That said, though, a lot of what is considered "punk" today abandoned those simplistic song structures of the 60s lo-fi/garage/protopunk (Stooges, MC5, Sonics, etc.) and started doing intricate and musically-complex studio productions. Including the band "Wire" which the comment I was replying to hails as a high achievement of punk.
Why not? Harmonic difficulty isn't a virtue. Jazz musicians were doing one and two chord and they are criticized for being obtuse.
Heck, difficulty in general isn't a virtue.