There are two types of filtering in this argument:
Hey, hey, hey. Someone went to a lot of work to do this. If nothing else, at least give them points for effort.
Anyway, I looked at them and while what you say is true, they DO look better. Many of them have what appear to be PS filters applied, and they look pretty nice. I'm certain that a map using these textures would look pretty nice (or could look pretty nice, in any case.)
Yes, Jdoom can filter the textures, but it doesn't increase their resolution. Resolution increase > filtering.
1) "Filtering" performed by Photoshop, ideally in order to make an enlarged low-res image look nicer, otherwise the enlarged version would look exactly the same.
2) "Filtering" performed by JDoom's renderer, in order to blur transitions between pixels so that the texture doesn't look like pixel soup when you approach it.
Photoshop filters are orders of magnitude more advanced than the filtering done by JDoom, this is because JDoom's filtering must be done in real time, once per frame, for each and every texture on the screen. This is a lot of processing, and this sort of filtering was the "killer feature" of the first 3d cards.
Photoshop does not have a microsecond limit for the length of time it can spend processing an image. For this reason, it can perform all sorts of bizarre operations when it attempts to make a low-data image look better on a larger canvas.
Now that that's out of the way, I would say that running a texture through some Photoshop filters does not a new texture make.
Some of the from-scratch textures are pretty good, but the textures that have been run through photoshop (I noticed the icon of sin textures in particular) although improved from their pixellated parents, seem pretty weak.
Someone else mentioned it, but it's true that the textures in this pack which take up megs and megs of space can be created by a 600kb computer program.
Also, releasing modified id property as a high-resolution texture pack is pretty bad form when the goal seems to be to create better textures.
Like, a lot of these textures belong to the "Doom 2 texture filtering project", not the "Doom 2 retexturing project". That's why it is disappointing to see them included.