The official word is that it was never banned - while most of us assumed it wasn't legal, it actually didn't break any of our rules or those of Takara from that generation (which was a big part of my "this should be legal" argument). The fact that good attack bases were so expensive before it was legalized probably played a part in how quickly the decision was made, though, as HMS/Plastics Remembrance was right around the corner.
The main reason I argued for it to be "legalized" is because it's the next best thing to Uriel 2's tip, in particular having decent (good, even) recoil control (unlike Customize Grip Base) and being compatible with Left Spin Gears (Unlike Grip Base) while providing similar speeds (better than CGB (esp. because CGB Self-KO's fairly easily), probably faster than Grip Base aside from while tornado stalling, nothing is faster than a TSing Grip Base).
But yeah, plastics rules are and always have been a bit sketchy - they evolved over time, too, and Takara's rules were not very detailed (eg they did say no extra metal balls could be inserted, but they did release a version of Draciel S with four metal balls as stock, which I assume was the justification for the four metal ball SG metal ball base thing thereafter, but I'm still not sure where four-ball Metal Ball Base came from, though it has a long and storied history even in official events, if I recall correctly it was what the guy who won the original US Championship used).
For what it's worth, I managed to recover my playlists (plastics aren't the only thing I'm pretty handy with
) so I will be around, though I'm kinda out of it today.