Not sure what you mean. They did it precisely for compatibility. It worked for FAT16 (and probably FAT12, for that matter) as well, and in fact long file names

Not sure what you mean. They did it precisely for compatibility. It worked for FAT16 (and probably FAT12, for that matter) as well, and in fact long file names came before FAT32. Anything that would trip up older DOS versions or any other FAT consumers was a no-go.