They're not going to until the absolutely feel they have to, because so many people (including myself) just keep letting our subscriptions renew.
This has got to be the only game I've ever played who had VIP benefits , then upped them because the original benefits weren't ,well, good, then cancelled those upped benefits without having anything in place to replace them, other than "we have some totally exciting ideas for the future, we'll let you know when they're done!"
I enjoy the game, although I'm only playing casually these days, but the VIP benefits have always been a joke, made worse by the Dev's teams "Oh yeah, we're totally working on making thm better, 100% on our radar/ put other buzzwords here to make it sound like it's something we think of"
It's the only game I think I've ever played where I've told friends, "Yeah fun game, but don't pay for VIP, it's not worth it"