I have a strong feeling that people of a certain age (say, born in the 70s) associate this kind of design with oldness, while younger generations have had little to no contact with it except in retro inspired modern design.
So, paradoxically perhaps, the older you are the older this kind of design looks. I'm of the age where it reminds me of old magazines and ads and stuff, so I see where you're coming from. But, I've also noticed that this kind of design has seen a massive resurgence in many areas of design. Mid-century modern furniture, interior design, etc. is all the rage these days. Many very modern companies and projects (the already mentioned Atom project being an obvious one) are using these kinds of design elements. Atomic and space iconography, subdued warm solid colors, non-traditional quirky (but simple and still quite readable) typefaces, etc.
I think that's it. The PDF clearly looks dated to me, but I think it's only some slight updates away from being something that could be produced today. (Different colors, clearer lines (which here probably is primarily limits of print and scan), slightly different fonts and typography)
