See? I feel the exact same about flat design. To me it dates back to the era of Tandy DeskMate, Windows 1.x and MS-DOS. I was glad to get away from it the first time. Going back just feels like reliving the '80s in higher resolution.
As for getting useful stuff working in iOS 6, you can thank homebrew devs, jailbreak and tweak authors, and third-party app stores such as Veteris. I just got a used iPhone 3GS and got iMessage, Mail, Weather, Maps and Stocks working pretty fast. I forgot how small it was! It's downright adorable! Also thanks to TubeRepair(BETA) the YouTube app works (both on iPad and iPhone 3GS) and no ads!
My Mac runs Snow Leopard too, and thanks to folks who made PowerFox a reality, I can browse the modern web on it.
Either way I am having an enjoyable time interacting with the UI I've missed since 2013. Also massive benefits to using a 3GS on WiFi only, as I'm unreachable when out, can touch grass without being distracted. It makes a dandy iPod.
I don't have issues with people who actually like flat design but I tried it and attempted to get used to it and I can't stand it. Hey, if it works for you all joy! Thankfully plenty of older devices exist on eBay cheap and still work.