Agreed, there is no timer in a transmission. Since I was 16 I've owned many used vehicles that I bought well past any warranty and still had original engine/trans and not all if any were serviced regularly, not even a fluid change. All of which I ended up putting 100,000+ KMs (excluding the few that were wrecked) on before I decided it was time for a vehicle change.
Its only recently that I've started purchasing new, but mostly because I like the new techy features todays vehicles have. With that said, I still own a 91 Acura and 05 Hyundai and just sold a 96 Ford that have about 200,000 KM each and are still running strong. Albeit, the majority of my cars are/were manual transmissions which might be a huge factor in my experience.