Because taking a K1000 on the road is a bulky package by itself. You might as well get a custom case w foam cutouts for a full size amp and the K1000s, put it on wheels and be done with it.
A GLite and its matching PS is a 'transportable' form factor but it doesn't have the muscle to drive a K1000. I can't see visualize hauling tubes due to breakage and the beefier SS amps are too big. Haul a Sig30, too funny.