They ARE awesome, but often come at the expense of time. I live in Tokyo, which has an amazing public transportation network.
Including walking to/from stations and bus stops, taking the bus/train costs me around 80 minutes of my day each way -- that's over 2 1/2 hours of my day.
If I take a taxi directly from my apartment to work, it takes about 15-20 minutes to get directly to work. Let's call it 40 minutes of my day.
I can get back two hours of my life every single day with point-to-point transport. That's two hours I could be catching up with friends, reading a book, cooking, exercising, etc. It matters so often to me that I end up paying the 4000 yen or so it costs to take a taxi twice a day a horrifying number of times.
This is to say nothing of the fact that I can sit in the taxi and read a book or something rather than being crammed and crushed in public transport.