iOS 8.1.2 did not fix the problem for me.
Neither my iPhone 5S nor BRAND NEW(!) iPad mini 3 still won't connect to some wifi networks, most notably free wifi networks in hotel lobbies, bars or restaurants
I went to the Apple Store with my iPhone and iPad and I got the usual arrogant smirks and comments ("don't believe everything that is posted on the internet") and the "technician" went on to try all the 'solutions' posted here and on many other websites, none of them work of course because I've tried them all myself already. He also did a hardware test, but the hardware works fine, as both devices had no problem connecting to the Apple network in the store and some other networks. When iOS 8.1.2 came out I immediately updated, but the problem still exists. Could it be that certain routers are causing the problem and iOS 8 somehow can't deal with it? I have an Airport Extreme at home, and that also works fine, although I have not tried out my new iPad on that yet.
IMHO, the worst is not that there is a problem. People make mistakes and problems are there to be solved. The worst is that Apple continues to deny that problems exist in the first place and that most of those "technicians" treat people like complete idiots.
p.s. My colleague with an ancient iPhone 4 with 6.1.3 on it had no problems at all logging into all the networks where I was having trouble with, and was laughing his butt off. I certainly feel like a fool having spent >$500 on a a brand new iPad Mini 3 (64GB) and not being to reliably use it online.
Thank you Apple!