Can you quote the lines from the book? Am guessing all that the author would've said is - you can't perform BMR on the target with an OS backup (of the target); but only with an RMAN backup (of the target). That is actually pretty obvious.

And NOT
BMR not possible in case of loss of catalog!
like you said.

All, I'm saying is you should be able to use the controlfile of the target to perform BMR even if you lose the catalog.

OS/Traditional backups can't be used for BMR, because of the architecture (RMAN rereads fractured blocks without need for placing files in backup mode). For one, there is no interface with a traditional/OS backup to say "hey, I need block# to be replaced on file#", then read all my backed up archivelogs, look if this block has changed, and if it did - replace it (just that one corrupted block). RMAN has this capability because it tracks the information - it tracks used/changed blocks.