Many people pray for others. Those are the people trying to force everyone else to pray longer. They feel jealous of the people who don't care as much about the deen as them. They see people leaving taraaweeh an hour before them and some part of them envies their carelessness. If you pray purely for the sake of Allah, you don't need others to do the same.

When you hold someone hostage in an hour of taraaweeh, you aren't doing them a favor. It just causes them to dissociate and it loses all meaning for them.

Most mosques in Muslim countries pray shorter but there are always certain mosques in every city that pray much longer so you can choose which one to go to. Deeds are based on your intentions.