It's indeed not a bad scent at all but I think the lable 'old people's frag' comes from the fact that it's marketed for the masses and that it's very affordable. I can imagine that some 40 years ago, men were not that busy with perfume and therefore this 'popular' and budget-friendly option was a bomb (the same goes for Old Spice and to a lesser extent Brut). And I can imagine that, being not that fragrance-minded, they just kept using this for the next couple of decades.
These days, men are becoming more aware of the joy of perfume and I get the feeling that it's not considered 'cool' to like Old Spice, Tabac or Brut, just because it's extremely mainstream, cheaper and ... stuff that grandpa's used to use (and still do).
A pity because I too like Tabac and especially Brut :-)