There isn't anything wrong with the stuff Lowes and Home Depot sells. Like you said, they are cheaper models that appeal to different customers, light users and for small yards. They are still there after 15 years so they must appeal to a lot of them. I was just surmising that if someone had a rider for 20+ years, more than likely the budget would fit into those type models.
I looked at a number of them and I think they look pretty nice. No doubt they won't last as long as a real heavy duty Deere mower, but the option is out there to tap into any price range.
I know a man who mowed commercially and bought a cheaper model Deere from a dealer and was angry that it only lasted two years. How he expected the the cheapest in the lot to stand up to everyday all-day pounding is beyond me, but as a rule, cheaper won't last as long as more expensive but maybe it is all that's needed or wanted.