I agree with your post - but I'd question this part. I expect to get many more years out of my BBQ's. I currently have a six burner that is around 13 years old - all of it spent in the weather with not even a cover. Just the hood. The chassis is finally crapping out & I have replaced a couple of burners, but it still works. Stainless body & plates - all they need is a wipe down. Empty out the water after it rains and it's good to go.
I probably should have pointed out it was a bit of an el-cheapo K-Mart bbq given to me by the in-laws... While it did the job Re cooking, the quality of the fittings etc was OK, nothing more. And like I say I gave it a decent workout, I'd typically use it Saturday and Sunday every weekend, sometimes 3-4 times a week during spring/summer. For what it was I was happy with the life I got out of it.