To be honest, i guess the whole idea with western comics going one way and japanese manga going the other never seemed to come to mind at all really until now at least, hah. A western comic usually goes left to right and normally always has, yet a western artist/author takes a stab at a manga styled comic and decides to go with the general manga layout of right to left instead? I'm not actually sure if that would really bother me at all. I'm looking at it this way, consider yourself Japanese and have lived in japan all your life. You've read through a lot of manga in your time and you see a western comic translated in a shop, you pick it up and you see its the other way round. You could consider the initial reaction similar to ours, strange, at least in terms of graphic novels, but would they see an eastern artist drawing a comic from left to right an immitation as well? The argument could happen there as well, but i expect they have a lot of left to right books there anyway, so which direction a graphic novel, or book takes, would be of no real concern.
If none of that made sense this may do ;p, I think that in terms of what your reading, it shouldn't matter at all in any regard. Why do you read manga? Why do you read comics? Is it the direction of which the book is read that takes you? or is the the plot/story/characters etc that takes you? Personally, story/characters etc are always going to be a must where-as the direction of which a book is read is, to me, trivial. It does nothing to deter the quality of the said graphic novel, and if it does, isn't that you mainly nit-picking above all else?