Trouble with that comment is when you buy one used. Unless it comes with service records, how do you know if has been changed and when?
I bought my 91 with 100,000 miles on it. It should have been changed once but I don't know for sure. I could just go ahead and change it anyway but that's a lot of work (or money) wasted if it was just done 10,000 miles before.
I plan to change it next summer as part of routine maintenance but at least I don't know to worry about destroying my engine if I guessed wrong.
Now that most, well not most, but how about "a lot" of cars come with a timing belt, the sensable thing would be to pay one kind of price for a car with full service records, and another kind of price for a car with no, or limited, service records. In your case timing belt breakage causes no internal engine damage, but in most cases it does, so the prudent thing to do is ALWAYS change that unknown timing belt. Again the prudent thing to do is to change the idlers, water pump, and carefully inspect the belt tensioner (for leakage) while "there".
I guess it all comes down to if you are into this thing for the long haul, or "just visiting".