Yes, it's optimized for German. But I'm sure any other language will be able to find a different use for the Umlaut-keys.
But: Even if you cut out those keys it's still 1337x more ergonomic than QWERTY/QWERTZ, which was designed for mechanical typewriters in 1878 and then never adjusted for the new reality of modern keyboards without hooks.
If you are interested in the specific advantages: wikipedia
Now why would YOU be interested in it though? Maybe typing speed or ergonomics don't matter as much as thinking speed for most of us?
First: Check out layer 3 and 4 of the layout:
All programming keys in a reasonable positions, arrow keys, a numpad, everything you need right there without the need to move your fingers anywhere else. A friend of mine who did not want to change from qwerty to neo simply uses a modified script that implements neo layers 3 and 4. It's a bit like the vim basics but everywhere available.
Second: Me and a friend started using it during our undergrads. I have convinced only three people since to change. But everyone of them is (having hated me for a few months) extremely grateful for having a reasonable keyboard layout for the rest of their life.
Third: It only takes a month of dedication and maybe three months of struggling if you really want to change to neo, not only add layer 3 and 4.
Fourth: For the lulz, there is only few people who can actually cause real mischief on my computer unless they manage to change the keyboard layout only by mouse. (I did not change the keyboard labeling).
imho, this layout should be spread through schools and universities, especially for people who will be coding most of their lives.
I can't fathom how any sane programmer can create code with a german qwertz-keyboard, see how all the essential programming keys are in the unreachable top row.
That's why (I hope) most programmers in Germany use the qwerty-layout which is definitely better, though still horrible compared to neo.
Changing perspective to a utopia, where children pick up neo from the start, they would scream at our standard layouts: WHY, WHY WOULD YOU SHOOT YOURSELF IN THE HAND?
Sorry for the polemics. But having a separate programming layer - and arrow keys and numpad and enter and backspace and tab and esc and scrolling keys and cool layer locks, etc. - just makes you wonder how any coder in the world would not use it. If you are teaching somewhere, please recommend or at least mention it. Everyone chooses their own tools, but most people just never wonder about the ~~stupid~~weird keyboard they got. I did, and I continue to profit from this.
PS: Most mainstream distros have had de-neo as a default layout choice in their installer as long as I can remember. So there is hope that more people know it than I think. It was only once that I met another person who knew the layout.
PPS: Layers 5 and 6 are neat if you want to impress people by how fast you can type Γρεεκ, but since a lot of software has trouble with encoding in real life you still use the LaTeX-way.
PPPS: ANSI-keyboards suck for neo. it still works, but you lose two modifier keys. You get used to it, but just better get an ISO-keyboard.