I started out on more of a leisure bike than I hybrid. I used it for about 4 summers. Last summer my riding style was changing (longer and I was more concerned about distance, cadence, shifting and getting more speed), I was ready for a different bike. My rides were consistently 15 miles and up.
Interesting note: in 3 summers I put 336 miles on my leisure bike, in 4 months I put 600 on my new road bike - it was just so much more fun than the leisure bike.
Difference with my leisure bike however and most hybrids is I had mountain bike style wide tires on it, along with a regular curved handlebar so I was sitting pretty upright (murder in the North Dakota wind)
Now to get to your question. My BF has a hybrid he has ridden for 10 years. He has done some touring on it. When we go out riding I have to push to keep up a lot of times and I am on a road bike. He has no interest in switching because it suits his style of riding, 10 - 20 miles on nice days
Had I gotten a hybrid instead of a leisure bike I probably would still be on a hybrid - they definately have their advantages. We are thinking of doing a rails to trails ride - the Mickelson trail in South Dakota, and hybrids are ideally suited to that road surface.
So not all people change over, it all depends on your riding style and goals. A girlfriend of mine wanted to buy my leisure bike and I tried to convince her not to because I told her she would soon outgrow it. She bought it, she loves it and is not thinking at all about moving to a different bike.
I don't know anything about urban bikes so no comment there.
It's about the journey and being in the moment, not about the destination