Rolls are easier to store and safer to ship, and account for most pro lab usage. Even Fuji has reduced their selection of cut sheets while maintaining virtually all roll products. During the recession
all kinds of mfg companies tried to cut back on "redundant" packaging options. Schools and amateurs
want cut sheet, so have largely turned to Fuji, who has kept it up to 20X24 in standard papers only.
Not nice for guys like me who want 30X40 in polyester stock, but that's why I have my own big
cutting table set up. The big digital printing machines generally have automated XY cutters on board.
Somone could probably pick up one of these slitters used for a few grand and go into business!