Apples and oranges.
Both games are designed for scalability -- for a fair comparison, look at Rome 1's medium, or Rome 2's high.
Can't run it? Guess what, most people couldn't run Rome 1's high back when it first came out either.
Gradually it will be optimized, and hardware will become cheaper and more efficient. Just like with Rome 1.
Your computer can't handle the graphics, that's why it looks so bad. When people try to raise the graphics that their computer can't handle the game for some reason makes it look worse. This has been put to rest.
I remember playing Rome 1 where I auto resolved all battles cause my PC at the time couldn't run a battle with more than 3-4 FPS. Now my mediocre, but not completely outdated, with an integrated graphics card can manage High no problem until it overheats and freezes. (though strangely the music keeps playing in the bg. Doesn't matter whether in battle or campaign map) I can't wait for some optimization and will probably look into some cooling and separate GPU.
Except that's not true at all.
After 10 years of developing, "Medium" is designed for your average, everyday consumer's PC, just like 10 years ago -- and just like 10 years ago, your average, everyday consumer's PC has very little capability graphically. If you have even a moderately powerful gaming rig, High is where you should go, for any PC specifically built for gaming, head to Ultra, and for complete overkill, go Extreme with unlimited video memory.
Kind of looks like your computer can't really keep up with the amount of textures that are being rendered so they appear all blurry and smudgey instead, possibly due to exceeding your video memory budget.
The amount of oversimplification in the OP is astonishing. Dynamic lighting, shaders, the poly count(I mean even on "medium" in Rome 2, the heads of the soldiers fully articulate they aren't just a round orb with a 2 texture slapped on), "graphics" aren't simply the sharpness of the textures....