Why don't you just stop judging and get him a visa if you so smart? I know it's 100% possible to bring the parents into the US, I don't know how but I know that it's possible which gave an answer to the original question. The person didn't ask how to bring them, he/she asked if they can bring their parents or not. Yes of course they can bring their parents without being the citizens of the US! But the choice of how to bring them is up to them.
vs4jamek got a reaction from CaizLurol in bringing family members of permanent residence to america