In a word: nostalgia.
Classic gaming is all about the fond memories of our childhood, and plastic cases were not used for games then. Those who grew up with Sega or PlayStation as their first console will have different considerations as to what fits the bill, but old-school Intellivision and Atari collectors and developers are very particular. I know I am.
-dZ.
Granted, but the ease of making a boxed game, when originally all you had was a cart only, or cart and instructions, is very appealing.
I have maybe 15 or so games without boxes. The sites online with the box scans and instruction/overlay sets are great, but not being able to print
a "real" box is what makes the platic cases somewhat attractive.
INTVNUT, are the cases you shared pics of, the same as the ones in the link posted by Revolutionika?
Thanks for the help everyone!