All recent Mac's have had a 64-bit processor. Lion is 64-bit and with Mavericks "free", why would Google continue to support basically Snow Leopard and earlier? I'm sure Google has run the numbers and there are very few that this would impact.
Eventually Google won't support XP either.
Google only supports a few versions back for browsers, so I can see them only supporting a few releases back on an OS as well.
Biting the hand that feeds IT
