I think I finally understand the arguments that some of you are trying to make. It's not that the official textures are ugly, per se, it's that they have more visual information/noise that make it more straining to play.
There are a few reasons for that. The biggest one being that the map geometry and lightmaps are very low-def and blocky. The textures need a lot of, well, texture to cover that up. I am legitimately trying to come up with a set of textures that makes the game, as it currently stands, look as good as it can. When textures are very flat, they tend to highlight the low map polygon count and blocky lightmaps, making the game look very dated or just flat out bad.
Another reason is lighting. If a texture is flat, it can end up looking completely washed out in bright light. If there is a lot of detail and darker shadows, though, it still maintains some definition.
Tiling is also a big issue. It's probably the most difficult one to address. Normally, textures should really be used for small areas and be broken up by different bits of geometry to avoid obvious tiling. Most paintball2 maps, however, have giant spans of just one single texture, like the walls in propaint1. They don't really make sense (where do you get 300ft/100m wide solid boards?), but the textures need to support that. What that typically means is reducing the macro detail in favor of a more uniform micro detail. Textures need a dense, uniform coat of rust, dirt, grain, etc. to make the glaring repeating patterns.
Finally, I'm trying to push the paintball theme. Nearly everything on a paintball field is worn, weathered, dirty, etc. I realize not everybody agrees with that direction, but this is a paintball game.
Regarding the "stop trying to make it look realistic" comments, this just seems silly to me. Not because people are arguing for a stylized texture set, but because the people complaining about it are using textures that are made from photographs. Many of these were poorly manipulated to tile and have glaring tiling pattern issues. This neither looks stylized nor realistic. It just looks bad.
As for oversized grass, the problem tends to be that if the grass is scaled down to realistic proportions, the blades are just like 1 pixel, so it ends up just being a green noise texture, which doesn't really look good either. Most of the alternative texture packs have large grass blades as well. Plus, when you're zooming around the map at crazy height and speeds, it kind of gives you the visuals that you would see as a normal human walking on grass, so doesn't that kind of fall under the category of not making textures realistic, but catered to the game? That said, if you can give me some specific examples, they can probably be tweaked without too much difficulty. On another grass note, I've noticed that a lot of texture packs (or maybe just specific players) replace all the grass in the game with the same texture. What's the point in having different textures then? Now there's no variation -- might as well make everything look the same.
One final note on the straining/distraction factor. Isn't switching to a texture set that reduces this pretty much define unfair advantage? If the background textures are less distracting, that means it's easier to see players. If you're selecting textures explicitly for this purpose, then you're not really picking what looks best, you're picking what makes it easiest for you to play. Where do you draw the line? Textures with less detail are less distracting than textures with lots of strongly defined detail. Textures that are a completely solid, flat color are less distracting than any texture. Where do you draw the line?
Please give feedback to help make textures that make the game look better.