iOS 10.1.1 was released even earlier in October last year. They simply didn't have 10.1.2 and went to 10.2, which certainly took a bit longer. So far this isn't really all that different from iOS 10, especially if you factor in a whole brand new and fairly different iPhone being thrown in addition to everything that's been there before.
It's a huge difference - this time last year people had only had to update their phones 4 times (3 if they didn't have iP 7/7+). This is already the SEVENTH public release of iOS 11 that's near or over 100% increase.
That's huge. And that's only sticking to the numbers and not even factoring in the rise in missing features at launch (3D Touch multi tasking, Apple Pay Cash, iMessages in the Cloud (how many did iOS 10 have?)), high profile bugs (8/8+ crackling sound, "I" autocorrect, calculator, 3D Touch lag, design slop, X getting cold (How many did iOS 10 have?)) and more anecdotal problems than previous years.
In ways you can measure scientifically (patch updates, missing features, bugs) and non-scientifically (complaints), it's a huge difference. And basically you can't really argue with numbers, you can choose to ignore them by saying it's not that different, but I prefer to work on evidence.