ToryBoy
I would not agree. The plastics you refer to are presumably mainly the instrument panel surrounds. These are of a similar construction to motor vehicle dashboard surrounds, and should last just about for ever.
I am not sure about Cessnas/Pipers being made to last, but it's hard to get good "data" on this since most of these planes are now very old (VERY few people in Europe buy new Cessna or Piper piston singles) and most have been badly abused in clubs/schools, whereas TBs tend to be privately owned and looked after a lot better. Especially the 1-door planes (PA28s) where passengers have to climb in over seats and consequently the seats get shredded quite quickly.
I've seen 20 year old TB10s and they certainly looked no worse than anything else.
If I was looking for a good mainly-VFR plane for reasonable distances I would go for a TB10 every time, over Cessnas or Pipers.