Non-technical reasons include "legal" and "compliance", which often matters a fair bit. I am not disagreeing that non-technical requirements occasionally lead to poor decisions, for some value of poor.
I live is a state that once tried to legislate that pi = 3.15. The results were tragic, and the attempt to legislate a ratio was a failure, much like systems created by regulation and laws often are. Math is much less forgiving than legal prose. Making database decisions based on criteria that don't make any engineering sense one way or the other is not far off from legislating the value of PI.
