I'm not sure a discussion of pedantic use of words will bring anyone to my point of view, but here goes.
When we refer to a group, what do we mean by "this group does X" ?
I think it is legitimate for me to say "English men like football". Not all do, but the majority support a team, and will cheer when the national side wins a match. Football is I recall the most popular participation sport in Britain.
Some hate football, I was brought up in England and (like me) never liked it.
But, although if someone made the assertion on MN, I might, like pagwatch say that I was a dissident to this.
But I would not say that they were wrong in that generalisation.
The OP felt that mentioning the Irish in the context of terrorism was racist. However, if one mentioned the English in the context of some soccer, I don't think this would be felt.
My position is to use the same prinicples whether it is something people want to be reminded of or not.
Yes, I have a personal grudge against the people of NI, that was of their making, not mine. Given that I was only 5, I'm not sure I even knew of their existence as a type of person until they tried to kill me.
Later, (at British taxpers expense) I became aware of Irish tactics in a bit more detail, and learned that they didn't want to kill me.
The idea was to scare people.
But under most legal systems, if you kill someone in an act that was intended merely to scare them, you are guilty of murder, and the IRA has made many such screw ups.
They apologise for this.
Yes, really, they send letters to the families.