I'm just not ready to buy the same stuff all over again anytime soon. Previous shifts in iterations likely followed changes in technology. Whenever that happens, I will likely be ready for something new.
I'd be happier to see them improve TS4, taking into account the feedback. I think that's very doable and to some degrees, is happening.
TS4 has been catching up on content that was in previous versions and then I think it should go into new and interesting territory. Starting all over again just isn't going to interest me by itself anytime soon.
It sounds like by shifting the focus to newer computers, they might be able to make more content in this version.
As I mentioned, if they want to make it so that you can port Sims from 4 to 5 and that 5 is more of a rebranding than a total break? Fine, sure, whatever. A lot of people are caught up in talking about the basegame and how it was released in 2014. Yeah, it lacked a lot and they've been patching stuff back in sometimes better than before. No, that's not a dig on previous versions.
We basically have people with numerous different playstyles and interests. It's a balancing act to please us all.