would gavin had created bitcoinXT had he known <1% of miners would support it, while >60% support BIP100. i don't think he would of wasted his time.
Gavin didn't create Bitcoin XT, he created BIP 101 and merged it to Bitcoin XT, which is Mike Hearns much earlier fork of Bitcoin Core. Miners show their support for BIP 100 for obivious reasons (it gives them more power), but we will see if it will be actually coded and if new fork will be created to implement it.
Also it's currently not possible to vote for BIP 101 as slush voting port got DDoS:ed and they disabled mining with it. In addition all Bitcoin XT nodes have been under constant UDP flood attacks and many have been forced to shut down. I'd say that statistics are meaningless with this level of censorship.
maybe he would of changed his mind and created a new BIP, but that's too late now, poor gavin cast away, forever?
I think that BIP 101 is a very reasonable proposition:
http://imgur.com/b5eOEafIt makes Blocksize limit growth predictable and if in distant future it errs to the upside it's always easier to soft fork to smaller value, than hard fork to increase, which would be must with BIP 100 and its 32 MB final limit.