Are you saying we should use 802.11a because it
works better or is somehow isolated from malicious or accidental
No, 802.11a is usually not as good.
That's why fewer chipsets bother supporting it,
and thus there was less interference for those which do.
This is simply a case where in a multiple-standard environment
the less prevalent one gains an advantage.
(Another case - less common operating systems and software
are attacked by fewer viruses.)
Ietf mailing list