1. You don't have to choose a sports bike, obviously. 2. My bike has a 1:20 usage (liters/km), that's a lot better than most cars I believe. 3. Do people really need a whole lot more stuff than they can fit in a backpack? Larger bikes with those cases attached can easily carry more stuff. 4. Weather would have to be really bad to stop you from riding (really bad = snow). 5. The front tire usually lasts several seasons, my rear tire costs some €150 and lasts a whole year. 6. Insurance is dead cheap! I pay €120 a year for my insurance, I'd pay at least twice as much with a small car. While a motor isn't always a good alternative for a small car, your arguments certainly don't hold very well either.