They did that, to save money on ink, and design. In printing color is extremely expensive and lucky if you even see it, inside of an instructional booklet. It is not like the printer for your computer. That is why you mostly see B&W print books, flying around over color. Color is expensive.
About design. The same thing occured with the SNES, Turbo Grafx, and so forth. It just seems that SEGA learned their lesson from the mistakes of the SMS. Just look at the box art of the American versions of most Genesis games. They looks like sex. Speaking of SNES, I don't get why the boxs are black. That must be alot ink, but again black is a cheapest color, next to brown, green, and yellow.
Also that boxart is Alladin, which was done in advance or taken right out of the animation itself. Seriously Disney......... That is the most cheapest kind of artwork, when you can find the same or simular image on an lunch box.
Look at Y's. Yes they might have reused the artwork from the PC game HARDCOVER book, but at least it looks like an monumental painting. The other one looks like they took it out an action sequence, of an animation/comic ( which is common ) of some sort, and re-did the characters.