Well, I understand your points, but actually it'll only work until the version you have no longer supports the OS you need/want to use, or until you want to change to a camera that's not supported. That certainly won't be "forever".
In fact CC even supports cross platform use/changes, whereas before you'd have to throw away one copy and buy another if you changed OS, or maybe even buy two copies if, say, you had an Apple desktop and a Windows laptop.
Also, even with CC, you're not forced to take updates. They are offered to you, much earlier than they'd be available under the old model, but you don't have to instal them.
But yes, you do have to be fairly sure you are likely to want future upgrades. If you are, it's a far more affordable and flexible system (maybe not if you ONLY want LR, not PS).
I know CC has been disliked by a lot, but I'd never have been able to afford PS without it, and if it protects Adobe's revenue from the thieves (70% of users I believe?), so it continues to be developed, I think it's a good way forward.
theres only a few quid in it anyway. download the trial and buy the disk and use the code from that.