If the goal of a DE is to attract users, Vanilla GNOMEs implementation fails to be attractive to most people as it is too foreign from established standards. Extensions are something that are actively not supported officially by GNOME, so using them would not fix the fact that a user expects a minimize, maximize, and close buttons and will not have them on vanilla GNOME, they will not have a Windowed start menu on GNOME, nor a System tray or traditional taskbar. What this user is saying is not "wrong" as they are saying the developers of GNOME want their DE how they want their DE, and people who prefer a more traditional desktop will most likely not like Vanilla GNOME because of that fact.