City Folk was not terrible, at all. Objectively speaking, as a game I mean. What you like and what you don't like about it comes down to personal preference. So while it had its flaws, people saying it was ''terrible'' without any sort of arguments to even back up that sort of claim kind of upsets me.
It was my favourite AC game partly due to nostalgia and partly due to how alive that game felt to me. It felt like a perfect balance between urban and country living! It added plenty of new things as a follow up to WW (town layout, slopes, house separation, house layouts, early pwps, graphics, city, Serena, flagpole, debit card, Phineas, the marquee, improved multiplayer, voice chat, I can go on-) and while none of those things may have been revolutionary, in my opinion they did not have to be. I enjoyed the game a lot; it felt like home. Nintendo worked hard on it and in retrospect I feel it was also a good transitioning game between WW and NL.
But on the topic of city living for Switch, I hope they don't take it too far. I'm a bit conflicted on the matter, actually. While I loved the feel of HHD, Animal Crossing has always been about small-town country living, and taking urban content too far could take away all charm! I won't be disappointed I think if they do introduce a city-like mechanic because deep inside I feel I can fully trust Nintendo, but I can definitely see why people would be a bit sceptical.