OH yeah I remember BTX, but that design was dated even for that time since it was only meant to stop Pentium 4s from overheating, not accommodate the monster GPUs of today. It was clever that it would Cool the PSU and CPU with one fan but it was still overall crap.

Also, just because a poor replacement suggestion failed once in the past, doesn't eman it's an excuse to give up on replacing ATX with something better.