Short nose gear
 

Why do some aircraft have noticably short nosegear?

Gulfstream come to mind. I can think of some good reasons, less weight, shorter airstairs, vectoring the thrust slightly upwards on landing, misreading the partnumber when ordering a replacement...

But what's the real reason?

More space in the nose locker for golf clubs?? :)
Balancing the G&T's level during taxying / touch down?
So's the SLF don't hurt themselves when they fall down the air stair? ;)
To get the engines facing towards the tarmac so's they can suck up more FOD??
:D :D

I have no scientific answer for you, only my own observations:

The lenght of the nosegear is not essential. Look at the CRJ200 vs the CRJ700. The 200 is level on the ground, the 700 looks like it has fallen on its nose. If they had not lenghtened the maingear on the 700, it would not have been able to rotate.
Many Airbusses have a nose down attitude on ground also (not the 320 series).

FS

Another reason for the CRJ-700's shorter nose gear is that otherwise, the exit door sill would have been more than 6 feet off the ground, i.e. Bombardier would have had to fit the EMG Exit with an inflatable slide instead of just airstairs...

Cheers