It's to do with what's known as 'Scotland's Secret Shame', IOW bigotry.
We still have a problem with the old Catholic - Protestant divide in Scotland. This hatred manifests itself daily mainly through the entities of Glasgow Rangers and Glasgow Celtic football supporters.
Traditionally, Rangers supporters were more or less all protestants and Celtic supporters mostly catholics. It's difficult to comprehend unless you live here or in Ireland.
'Bhoy' or 'Bhoys' is a name that Celtic are known by, The Celtic Bhoys, which I think was originally a spelling mistake! I could be wrong though.
But I know people who wont watch Danny because they think his surname means ne is a Celtic supporter, and I have no idea if he is nor not.
The whole thing is n embarrassment to Scotland, the Scotland's Secret Shame reference was taken from a speech by our then first minister Jack McConnell.