As Kenwyne says above, many Welsh people are passionate about our anthem.
I can accept that splotty doesn't like it, but he's a lone voice imho, evidenced by how thousands of us spontaneously sing it during a game.
It is a celebration of our history, our culture and our language.
If nobody bothered singing it, maybe he'd have a point, but until then "bydded i'r hen iaith barhau"