There is nothing wrong with the one we have, this debate started way back when some foreign bands had difficulty playing The Soldiers Song.
The loyalists have their own culture[fucked if I know what it is except sectarianism] and the nationalists have theirs.
Peadar Kearney in 1937 added an extra verse to The National Anthem to include the north but was not embraced.
If this debate was brought up in England or America where their anthem was to be changed to accommodate some ethnic minority there would be uproar.
Only two weeks ago some Polish bouncer stopped a singer from playing our national anthem in a Dublin pub stating-We Have A Mixed Crowd Here Tonight-what next.

The extra verse of the Irish National Anthem can be seen here

on my site