[U-Boot] bad block handling for NOR flash?

[chris warth]

Can anyone help me understand why common/env_nand.c has bad block
handling, but common/env_sf.c does not?

env_nand.c writes uboot environment to nand flash and explicitly skips
bad blocks.
env_sf.c also writes writes uboot environment to flash, but does not
have any bad block handling.
For my board, env_sf.c is writing to NOR flash over SPI bus.

Is it the case that NAND flash parts have more defects than NOR flash
parts, so bad block handling is essential?  Or is it just that nobody
has gotten around to adding bad block handling to env_sf.c?  Something
else entirely?

Thanks in advance for any insight.

- Chris