Old pianos are no good...period. Unless they are completely reconditioned (as many are).
An incorrect generalisation like this is what lies behind that article. In wealthy areas near me, there are lots of quality old German pianos, played, but not abused, nice crisp actions, original strings, not rusted, some restrung, going for a song. Much nicer than new low end Chinese imports will ever be, and the likelyhood of getting your money back on sale.