I think not suffering from websites saying "sorry, iOS is not supported" qualifies as a superior browsing experience.
I think not suffering from websites saying "sorry, iOS is not supported" qualifies as a superior browsing experience.
You'd easily be shown to be the asshole when a jailbreaker or someone with a proxy spoofed their user agent and loaded your page just fine. Not supporting a browser without a valid technical reason that the layperson can ever sort of understand will totally undermine your position.
Only 5.9% of Android users are on obsolete 2.x. 5.1% are on 4.0.x, for which Chrome was just EOL'ed at version 42 (http://blog.chromium.org/2015/03/freezing-chrome-for-ice-cre...), which compares very favorably to the current and previous versions of Safari (http://caniuse.com/#compare=chrome+42,safari+7,safari+7.1,sa...).
Ultimately I'd think the only noticable effect it would have is the 2s it takes users to navigate away from the site to never return again.
[1] For the life of me, I have never understood how childish one has to be to have an _emotional response_ to something like that. Whenever people would ask me my opinion and I'd state why I chose X over Y, they'd project "Wow you really hate Apple" onto me for some reason.