Could the pictures be posted of every tartan that is actually made into a kilt? YUP!
Does it take a ton of web space to do it? NOPE!
Should it be done? YUP!
How can SportKilt do it? Their stuff is "pre-fab".
How can UtiliKilt do it? Their stuff is "pre-fab".
How can AmeriKilt do it? Their stuff is "pre-fab".
Why doesn't USAKilts or BearKilts do it? Their stuff is CUSTOM MADE to length, waist, hips, stripe, field, etc, etc. (That's why they fit better).

Many of the CUSTOM kiltmakers rely on their customers to send-in the pictures as testimonials. SO... those who want the pics... send them over and they'll gladly post them (I'm sure). It's REALLY not that difficult of a task.