No one would ever, for economic reasons, plan (or just allow) for the lifespan of their products to decrease. http://resource.co/article/lifetimes-household-appliances-be... Technology is always getting better!
The old timers who almost universally report this phenomenon just don't know enough arm chair statistics. Delusional, basically.
If a study were done, or a set of studies, say between changes in average appliance lifespan between 1993 and 2007, these could never show a dramatic decrease in the average lifespan of most appliance categories.
1993 NAHB results http://www.metrohome.us/information_kit_files/life.pdf
2007 NAHB results https://www.interstatebrick.com/sites/default/files/library/...