What is the reason behind changing the name of well-known apps?

> MATE has forked a number of applications originating as the GNOME Core > Applications, and developers have written several other applications > from scratch. The forked applications have new names - mostly in > Spanish: > > Caja (box) – File manager (from Nautilus) > Pluma (quill) – Text editor (from Gedit) > Eye of MATE – Image viewer (from Eye of GNOME) > Atril (lectern) – Document viewer (from Evince) > Engrampa (staple) – Archive manager (from File Roller) > MATE Terminal – Terminal emulator (from GNOME Terminal) > Marco (frame) – Window manager (from Metacity) > Mozo (waiter) – Menu item editor (from Alacarte) What it use different name for well-known programs? It make user confused (e.g. gedit foo.txt breaks and I have to run pluma foo.txt) They are almost the same as the original ones. Wasn't it better they send their modification to main branch?