Don't get me started on this. I don't like the 8x10 format either, and feel the same about the 6x7 negative. It's just not a good format for composition. I wish the paper companies would make papers in sizes that made sense, because 8x12 is the correct size for 35mm, and I am not happy about wasting so much paper when I print 6x6 either. 8x10 is an OLD and obsolete format from the days when a lot of people shot 4x5, so 8x10 is the natural progression for that. When 35mm became popular, nothing changed. It's not hard to make papers the right size. Look at artists sketch pads. You can buy them in all manner of formats, even square.
Then, often you'll see frames made up in completely different formats! If I frame something, which I rarely do anymore, I have to make the frame and mats up from scratch.
It's not like they actually make papers in these sizes anyway, they're cut down at the factories from large sheets. Only hand made papers w/ full deckle edges are in the sizes they were made in.