My impression after installing Windows 8 on 2 desktops and 2 laptops is that Windows 8 is worth installing if one can afford it. It's a more stable and snappier Windows 7 with a few useful additional features, e.g., bookmark synchronisation between Windows 8 computers, more embedded anti-virus program, and enhanced or perhaps meticulous multi-core/thread performance. Also, the booting time has been considerably reduced, which is why I installed another Windows 8 on my HTPC lately.
I am going to pick apart your brief critique of W8 vs W7 - please don't take this personally, this is just what I see day-in day-out.
Price - depends if someone is buying new, at which point its a non-issue, and I don't know anyone who has bought Win 8 to install on an existing system.
Stability was never an issue with W7, so your point holds no value.
Snappier, only if you can figure out how to use a PC with a vastly different interface to all previous versions of Windows. To me, who has used every version of Windows from W3.1, W8 is distinctly less-snappy - although to be fair, if this is the first OS that you have ever used its no different a learning curve to any other.
Bookmark syncronisation between computers is only any good if you have (use) more than one, most people don't. And businesses are refusing to use it at all.
More embedded AV, its so embedded that it stupidly doesn't even make the end user aware of its existence, I have encountered a few W8 PC's that have serious problems because people have installed an AV program, PC's really don't work well with more than one AV program and can actually become unusable. This is a massive cock-up on MS's part and is unforgivable.
Whether W8 has better core/thread usage is irrelevant to most users who never tax their systems, Power-Users might find this useful though.
Boot-up time has been considerably reduced, as has the shut-down time. This is great news for the army of (cheap/average) laptop users, but makes little/no difference to power users who wuill be using a SSD anyway.
The main drawback to W8 for me and most other people is the hideous UI. The UI has been designed for touch-interfacing, and falls flat on its back for 99% of users. The learning curve alone is extreme, and I have still only met one person who actually "likes" the new UI (although she keeps on asking me how to do stuff, which I always respond with "I don't know", so that's of little value).
On a personal level, when I have the sad misfortune of having to sort out problems with W8 machines, the first thing I do is to install "Classic Shell", which never gets removed when the customer (I am a computer engineer) collects their PC. Most peopel want to kiss my feet for making their W8 machine much more like W7.
To summarize. I have no issue at all with people who prefer to use "X" OS over "Y" OS for whatever reason (I know a few people still happily using XP, Mac OS, Linux), by I wont stand by and let your above reasons "why W8 is better than W7" go unanswered, especially as you have given "your" reasons which are unlikely to be the same as "Average-Joe's", and I certainly shall not berate you for preferring W8 over W7 or other OS's, that's your personal choice.
The one thing that I absolutely cannot stand about MS is that they have "forced" the average end-user to buy a (new) machine with an OS that they cannot use, hate using and causes them huge amounts of grief. If MS simply allowed people the choice of W8 with the "new" interface, or W8 with the "old" interface we wouldn't even be having this discussion, and I wouldn't be removing W8 and installing W7 on peoples brand new computers or even installing "Classic Shell" on them. Are you listening MS, people like "choice", give it to them, let people chose which interface they use on their own computer.
The amount of people that I have met who:
(a). Like the W8 interface - 1 (2 including yourself, although I have not met you in person).
(b). Dislike (or even HATE) the new W8 interface - hundreds (that I have met personally).
(c). Are so disgruntled with MS they have started using Linux, about 10.