I ride a hybrid because I like to be upright. Both so traffic can see me, and so I can see everything. It's also very comfortable for me. Bigger tires too, which I prefer. And my hybrids are pretty fast - quite a bit faster than my mountain bike with street tires, which I like, but there really is no comparison. Fast = Fun. Oh, and the chainstays are long enough for rack/panniers. Fenders, attachment points. So many reasons.