The cross generational releases were actually a pretty recent trend. Between the 6th and 7th gens. It really wasn't a thing prior to that.
I'll say it's a bit odd that developers would skip the time it takes to do a scaled down port for 7th gen titles, but hey; I'm not privy to their spreadsheets and I have no idea what their accountants estimate would be the results on extra cost of development relative to the extra sales they would have on legacy platforms.
On the plus side, it does give developers something to use for marketing and PR if their game supposedly pushes some technological boundaries or makes legitimate use of the greater resources 8th gen platforms have to offer.
On a consumer level, it does let new adopters feel more justified in their purchase and maybe even buy a few more games they wouldn't have normally bought, but do because they're exclusive to their new console.
It'll be interesting to see how long cross gen support lasts. For some titles, it makes sense in terms of market size, while other titles might benefit from the illusion that they simply can't be done on older hardware.










