You like endstone, but you think it ugly? Faithful looks fine? I'm sorry, but that makes no sense. If you're saying people use endstone because it looks good in Faithful, then you completely missed the point. I've never seen an epic build anywhere that used endstone as the primary material. I'm sure you can find one if you look, but there's a reason you would have to look hard to find it and not just stumble upon it.
Also and I'm trying hard not to make this personal, but if you're not planning on using vanilla Minecraft textures, why do you feel the need to personally disparage they guy working on them, JAPPA. Everybody agrees some of the textures are bad, but no one agrees on which ones.
It's not going to be possible to make everyone happy. It takes a pretty brave soul to even try this. Can we try to offer constructive criticism, and specific helpful suggestions instead?
For example: you stay, "This is hideous. I mean, really, really hideous." is completely unhelpful. Instead, say what you object to, and how it could be corrected.
A comment like this might be more useful to the guy.
I think the Cobble looks like... well Cobble, the rounded pavement stones used for streets long ago. It would look good as a road material. Unfortunately, it does not work well as a building material. I would suggest making the "stones" larger with less dark material in between.