If you go, lets say, 3D Models-car, and than choose 3d print on the attributes tab, it will show you models that are (considered as) 3d printable, why some of those 3d printable models are stolen from video games and why they are low poly it's a separated topic. Not every high poly model can be used for 3d printing so option to filter between high poly and low poly models is useless to someone who is only interested in 3d printing.