We're already on DST 2/3 of the year; it's considerably less disruptive to keep it year-round than to switch to all standard time. Not to mention many of us find DST strictly superior given the common work/life schedule. In the summer, standard time would mean it gets light even more ridiculously early than it already does, so you just lose useful light, rather than having it to enjoy summer evenings outdoors. In the winter it's certainly more of a preference thing, but there are plenty of us who would sacrifice light in the morning for more light after work.