Like everybody else here, I think it depends on the person and on the situation. We have six cats and will not take anymore because, financially, we can handle six. One more just might break the bank; I know how silly that sounds, but it is what it is. DH and I have agreed, too, that as these cats pass on, we will not be bringing more into the house. He agreed to Mollipop, but I think that was because I was grieving so terribly after Banshee passed on. He knew how badly I was hurting and when I talked to him about Mollipop, he wasn't real happy, but he agreed to make her the youngest RugCat. (And you should hear how he coos to her and lays with her....he loves that little girl.) People have looked at us when we mention that we have six cats, but we're so used to it that we don't care anymore. Now that our son is grown with his own family, those cats are our kids and we take care of them. All of them (even the little brat who wants breakfast at 4:00 in the morning!)
I've heard about people who have so many cats that they can't take care of them properly. I've heard about people whose children were sent home from school because they stank so badly of cat urine. People who have gone on vacation, come home to piles of feces all over the house, evidently because they didn't have a cat sitter....and were too tired to clean everything up before they went to bed that night. A friend told me one time of a woman whose cat pooped in her hair braids.....she just cleaned them as best she could and left them go. Now THAT'S too many cats combined with a definite lack of housekeeping. If you have cats, you need to keep after them. Every single day. It's a law or something (being facitious here

. But you know what I mean.) When your kids are sent home from school b/c of pee odor, there's a problem.
OTOH, there's a lady in town who lives in a gorgeous three-story house. The top floor is completely devoted to her 14 cats. Cat trees, toys, beds, litterboxes, the whole bit. Those babies lack for nothing. She'll come home from work, make dinner for her furkids, make her own dinner and go up to the cat's floor and spend the night with them. The cats are allowed to roam the house and they do from time to time. But, for the most part, they're perfectly content to stay on their floor with their comforts. It's amazing to see that floor and everything that's there strictly for the furkids!
When I was the Zoning Officer in town, people would call the office to speak with me about a project they were working on at the time. They would say, "You know, I don't know her name, but she's a cat lady and she drives a red Cruiser!"