[rakoo]

Because iOS doesn't let you do that (see http://op-co.de/blog/posts/mobile_xmpp_in_2014/#index6h2)

[pjc50]

This is the real answer - long-standing connections are banned by the platform monopolist - and should be much closer to the top.

[emias]

Yes, but I think the claim was that a persistent TCP connection has a negative effect on battery life, which is not obvious to me. An idle connection should have no impact whatsoever.