Thing is though, sometimes stupidly broad scottish accents come from whos influenced you and not an attempt to sell out. I myself fell victim to this, not ages ago a heavy scottish accent started creeping into my songs; not as an attempt to "cash in" but because I happened to be listening to a lot of Arab Strap, Sons and Daughters, Xcerts and Woomble. All of them have broad scottish accents. Sometimes you unintentionally rip off your favourite bands chord progressions or riffs, i dont see why it isnt entirely possible to do that with accents.