Some people hate it. They feel that driving is a hassle, or confusing in an unfamiliar town, or that it's hard work, and they prefer to sit back and let Disney do the driving for them when on vacation.
I'm the opposite. To me, driving is like breathing; if I can't do it for myself, I turn blue and pass out. I rent a car on all of my trips, whether I'm staying on-site or not, and I drive just about everywhere. By self-driving, I save TONS of time over the WDW buses, I have total control over my own schedule, and I can change plans at the drop of a hat. I can also go off-site any time I want for shopping and dining, and for my mandatory visit to Universal Studios.
MK is the only destination where driving is not faster than the buses, because the buses go directly to the park gates, while the parking lot is at the TTC, on the other side of the Seven Seas Lagoon. To get from TTC to the park, you have to take a monorail or ferry boat; but I don't mind that at all, because I regard the monorails and ferry boats as attractions, not transportation. My Disney Day doesn't start when I reach the park gates - it starts the moment I get on the ferry in the morning, and doesn't stop until I step off the monorail in the evening.