That's true of almost every big computer monitor. My HP ZR30w has a couple display port inputs, and the 30" Dells around here have a single DVI connector. Neither have OSDs or support any resolution other than their native.
Dell U2711 has every kind of input known to man (well, the currently popular ones, anyway), has a decent OSD, and supports every common resolution starting from 640x840. The 30" from the same line is no different.
That is quite strange, since I've never seen a 30" monitor with any "extra" features, nor have I read a review of one. I assumed it simply wasn't done.
I was very surprised when I got a 30" monitor with more than one input.
the 30" dells you see are the 3007, it just has a dual link DVI input and no OSD. All the newer models 3008 and 3011 have a plethora of inputs:
2x DVI
1x DP
1x HDMI
1x VGA etc
My 27" Dell is covered in ports (5 inputs of all kinds, USB, CFCard, SDCard, you name it...) and has a pretty fancy OSD to go with the 5 physical buttons and 6 LEDs.
Granted, I don't actually use any of the ports other than DVI and USB, so it has always seemed a bit overkill to me.