Not sure about that -- there seems to be a whole community that self-identifies around power-pop-as-genre. My friend and former professor just wrote a book on Shoes, for instance, and the discussion of it has fairly well-established boundaries:
Maybe this is just within rockcrit, where when you ask someone to name power-pop bands they will likely gravitate to the 70s-80s stuff and then on to Matthew Sweet and Adam Schlesinger/Fountains of Wayne. (Jonathan Bradley persuasively argued that One Direction are, musically, post FoW power-pop.)
no subject
http://blog.musoscribe.com/?p=4394
Maybe this is just within rockcrit, where when you ask someone to name power-pop bands they will likely gravitate to the 70s-80s stuff and then on to Matthew Sweet and Adam Schlesinger/Fountains of Wayne. (Jonathan Bradley persuasively argued that One Direction are, musically, post FoW power-pop.)