And many who do, don't think about the future beyond their lifetime and perhaps their children's.Not sure one should confuse Science fiction with the future.
Not all science fiction, but if you follow science fiction broadly, you can't avoid at least a passing glance at how our present actions might affect the future. Many though not all who don't follow SF do avoid any fleeting thought of the future beyond their lifetime and perhaps their childrens.
I don't think being a scientist or a politician requires reading SF. Nor do I think reading SF makes you actually think about the future in realistic terms. A lot of SF is pie in the sky leaping to from point A to point E and avoiding the messy stuff in between.