Some discs don't actually require purposely-altered EDC/ECC data, and just use normally constructed ones. In such cases (PC games usually), you can generate a 2352 byte/sector "dump" from a standard 2048 byte/sector image (I don't know of much that can do this... besides using a CD drive emulator like Daemon Tools or CDemu then using the dumping apps) that is identical to the normally-dumped method. In certain cases, this will never be possible (eg, PSX).
And the creators of the ISO 9660 standard had no concern in this matter. It's a filesystem and it wasn't their duty to dictate how CDs store information in the low-level manner, that was Philips' job (see ECMA 130 for details on the physical layout of CDs and the low-level 2352-byte sectors). You can also store ext2, FAT, UDF, any other filesystem on a CD, and it's of no concern to those filesystem authors what the low level CD format is.
(Technically speaking, redump.org DVD images are all wrong since they don't include raw DVD sectors, which is far more difficult to access and not all DVD drives do it in the same manner (essentially every vendor has their own proprietary commands); who's to say that non-chipped PS2s actually check data that's not in the 2048-byte user data area of a DVD sector?)