People who don't take the time to know their cats write cats off as being jerks. They're pretty complicated and self reliant little buggers. Whereas dogs need to be walked and taken outside for potty and so-on; cats need play time every day but also their own space.
To clarify, I just meant that as two differentiating aspects of dogs and cats. If you're not ready to take care of your pet's needs then don't have a pet, dog or cat. Also, dogs definitely need playtime too. But dog play is different (in my experience) than cat play.
Well, you can get a 'cat toilet'. A lot of them are pretty terrible, but once you get around the mid-range price of 300-400, they mostly have all the kinks worked out, and you can install it to connect to sewage like a normal toilet.
The one downside is that pretty much all of them use plastic beads as the litter, and sanitize with heat. This means if anything malfuctions, then you get the smell of burning fecla matter and plastic.