Honestly, I get the reasoning behind the accent, but I think maybe part of what makes it so distracting (at least for me) is that accents in text just don't work to begin with. I think it's a pretty natural thing when you're reading to just read in your own natural way of speaking. Except in cases where I'm reading something for which I've seen an audio/visual adaptation or tie in (and therefore have a feel for the character's voice and accent) When I read, in my head, everybody just has a neutral american accent. And as soon as I hit a "ye" or an "aboot", all of a sudden it's a neutral american accent that is forcing in random words from a scots accent.
That doesn't read as an accent, that reads as a bad impersonation of an accent, and that's what makes it hard to swallow. It's like somehow the experience of a bad dub has been translated into text form.
I do think the page at the front of this update was worth including, though. It was less distracting having a more thorough explanation of the reasoning at the beginning.