each person does different things with thier car, i use mine everyday from going to work to going to the store for groceries and carrying my wife and daughter around. having a seat that will not recline or tilt forward does nothing for me. and i also go on quite a few really long road trips and i would rather have my cheaply padded oem seat over any aftermarket plastic/aluminum/carbon fiber seat that was not made with comfort in mind.
some people go for different looks, not sure what your car looks like or what kind of look your going for. i have seen a few cars that have them and i thought it looked good but its just not for me
just my thought on it, you asked why and there you go
I've seen some racing seats (By Spearco) that do recline. But they're expensive.
It's safe to say, if you weigh over 200lbs a racing seat isn't for you.
Your hips and legs would be hurting shortly