How can 30-year-old receivers sound better than new ones?

Well, how?!  This article explains...note it's from 2011, so we should be asking how 35-year-old receivers sound better.  Ever mindful!
Rarely have I owned receivers that were NOT 30+ years old... at various times I've had a Technics SA-400, Harman Kardon HK660, Nikko 301-T ("obtained" from Eric Carmen), Fisher 500 (and a 450-T), and I've never been disappointed.  So maybe I'm not the one to ask.  Stop asking.