Philip was born nearly 100 years ago....
So?
My Grandad was born nearly 81 years ago now, not far from 100. Realistically, that isn't a huge difference as social trends and beliefs didn't change all that much back then. I can understand that things have only started progressing so drastically relatively recently with the rise of the internet, hence why so much obviously bad crap has existed for hundreds of years and is only coming to light and changing now in the space of a couple of years. Hence why those mindsets are still engrained into many including the generations pushing for that well needed change.
My Grandad however was not a massive racist, neither is my grandmother who is obviously in the same age range (though slightly younger).
Age isn't an excuse for poor behaviour and dated harmful beliefs. It isn't "too late" to admit fault and start treating people decently. Sure, I expect somebody who has had those beliefs drilled into them for 100 years to let the odd remark slip once or twice out of habit, nobody is perfect, but I also expect they would apologise if they truly meant no harm, not have the rest of their family apologise on behalf of their backwards grandad as they waltz off and continue to do it.
The only difference is mindset and clearly Prince Philip had the mindset of "I do not ruddy care!", maybe not helped by there being near no consequences for his actions. If the husband of the Queen of England can't be held to a higher standard and fails to hit a higher standard than some random dudes grandparents, well, I would say he shouldn't be in that position of power and influence at all...But I guess he's one step ahead of me there...