Obviously not for 'purists', but considering the preponderance of effects most guitarists end up using it's a much quieter way of getting a waveform off the strings and into the signal path.
Just watch, the first time someone uses one of these on stage with a lot of pyrotechnics the resulting noise extravaganza is gonna make that Merzbow guy sound like Ed Bickert.
I would guess they didn't spend the time and effort to patent a pickup that freaks out under flourescent lights and camera snapshots. I could be wrong though.
Me, I'm waiting for the 42 fret model, and nothing less.
Weeell, traditionally guitar fretboards stop at 21 or 22 frets because halfway along the string is where the first harmonic sounds, and if you put a pick-up there you get a full, rounded sound. There's no physical law stopping you from putting one there and many shredder-type guitars have 24 frets. The only practical reason for stopping around 22 is that the frets get stupidly close together. The 25th fret on this guitar will be 8mm from the previous fret which, if jumbo frets are used, gives you about 6mm to press down on. I was surprised this uses a relatively short scale length: if you really wanted to show off you'd use a longer scale length. A 28-inch baritone neck for example would allow you 28 frets before you hit the 8mm spacing.
And in response to GL's actual question. 25 frets, I suppose, is one higher than 24.
A bit of Internet research though reveals Uli Jon Roth and his 30 fret, 7-string sky-guitar: http://tinyurl.com/getf8 - the sky guitar is almost as ugly as the one in this post.
As for optical pickups, didn't we all get excited about lightwave pickups not so long ago? http://www.lightwave-systems.com/
At least they can shape a body...
To contrast here's the really rather lovely Maccaferri-style Eimer, with only 26 frets, but it is an acoustic: http://www.eimers-guitars.nl/EG-Pizzarelli-LS.jpg
Optical pickups are nothing new, and this "guitar" looks like it was made by special needs kids during a one-day workshop. Hoag, the inventor, invented these back in 1968 and first showed them at NAMM in 1969. As you can see, they're catching on.
Note that the actual bridge is under the pickup cover. That bit of rectangular metal you see below it is a name plate. Palm muting is almost impossible.
Also, external power is required for the light guitar... Less than optimal.
Having tried them, they work well. The tone is a bit sterile but clean.