Logical argument. Vice versa - if songs of any languages are allowed, then request for songs should also be allowed.If typing the lyrics of other regional language is wrong then the source of that action i.e the song which has been posted is also wrong.
Yes music has no language but music combined with lyrics has language which we are calling a Song..
We can't say Tamil music, Hindi music, Bengali music but we can say Tamil song,Hindi song, Bengali song etc..
So mute or ban the one who posting the lyrics is right then the mods or admins should mute or ban the one who post the other regional songs too..