How many "Thick server/ thin client" <--> "Thin server/ thick client" cycles in the last 30 years of computing? Four, five, maybe six? It would be interesting to determine the frequency, so we can always be prepared for the next wave... Anyway you can absolutely trust that in less then seven years you will be on the "thick server again", so you can polish your PL/pgSQL+PL/R when you see it coming.
Remembering: thick servers are much more efficient in terms of energy, heat and per-dollar-computing, but thick clients are much more interactive. Thick servers tend to centralize the data, which leads to sloppy crypto and security, which leads to "I want to keep all my data on my cabinet/table/person/skin? at all times", which leads to "where is the last backup", which leads to "oh, I'll just trust the cloud with this, because surely Google and Amazon replicate the data and keep timely backups" etc etc etc.