Amen to that! Your neighbour sounds like a douche nozzle..
I have four cats (yes, I know that's a lot of cats) and they don't roam free, never have. They're not stuck inside all day every day though, they have a pen that they go in when its not raining. The pen comes off a window so they go out the window into the pen. They can't get out of the pen into the yard so the wildlife is safe but they can still feel the grass on their paws and the breeze in their fur. My eldest turns 10 this year and my youngest turns 3.
The younger one has never known a time where she didn't have a pen to play in, and the older ones have almost always had a pen with the exception of a few years back (2014) when we moved house and couldn't bring their old pen so my ex had to make them a new one and they were pen-less for a bit over a year.
The fact that they have a pen is what annoyed me when pigeon guy threatened to shoot them. Its like "dude, they can't get to your stupid birds so why are you worried? You didn't even know I had cats until you seen them in the pen! Your birds are more likely to destroy my property than my cats are yours so shut your pie hole!"
I think all pets should be confined to the property of whoever is responsible for them, there are soooo many good reasons to do it and it isn't really that hard yet I know so many idiots who let their pets roam the streets..