Honestly, I think it's too black and white to say 'x age is too old to be a father'.
There are so many things that can happen in life, so many things that can change the 'plan' you had in your head when you decided to have a child. You could have a child a 20 and then die of cancer, you could live until you're 96 (like my grandad) and be active and happy the whole time.
A couple with an older father could stay together for the rest of their lives, and provide a loving and stable home for a child, whereas a younger couple might divorce and remarry several times, making life for their child unhappy and difficult.
An older father could be financially secure, have a good house with no mortgage and really be able to provide for their child - maybe even take early retirement to spend more time with them .. whereas a younger family could struggle with debt and mortgages and trying to balance career progression with raising their child.
Happy homes come in all shapes and sizes, and yes, you know what, statistically speaking if your dad is 60 when you're born, you're going to lose him much earlier than you would if you were 30. But life is full of sadness and challenges. All loss is difficult but it comes to us all, and the years of living in a happy home are remembered fondly.
Losing your father hurts whatever age you are, but with so many different things in play to decide whether someone is a good father, or a childhood is happy, it seems far too simplistic to simply say that an older man shouldn't have a child.