The mobile site here was created before there was a Android phone in its current incarnation. Android at the time was like a blackberry. No touchscreen, hardware keyboard, shitty browser. It was about a 20 months after the launch of the iPhone before there was a Android phone that looks like a current Android phone.
The mobile site here was created before anyone knew that Android would end up being a real product.
Fluther got big fast when Apple highlighted it on their website of the list of webpages optimized for mobile (this was long before the app store).
So calling it i.fluther.com shouldn’t be all that surprising.