Rules are subject to change. The argument of 'just because you can doesn't mean you should' is what they were trying to get across with the somewhat clunky analogy. Also, Devs and GM's have stated multiple times that 'difference in playstyle' is a valid kick, not just the options listed in the drop down menu so there your argument breaks down.
You claim to have a count, I have a lot of folks I asked going 'That doesn't seem right' hence why I brought it up.
You're not being punished. People who had their houses demoed weren't being punished. You didn't do anything wrong, thus you are not being punished. What could possibly happen is you may be negatively impacted by a change in rules. As the other half of my post said there are things SE could do that would allow you to keep multiple houses. However, we've all seen that SE likes to use band aid and that's exactly what this is, a band aid. There are plenty of vastly better fixes but can you name one that's faster and cheaper for them?
I named several better fixes in the end of the post that you didn't quote. Dynamic wards would be better, suddenly there are enough houses that everyone. Only downside would be a lack of size options since you'd have to rush a new ward for a large or medium but it would almost ensure a small per character. Vastly improved instanced housing would be better, if you could upgrade the apartments from a tiny room into a mansion-sized penthouse with rooftop patio wouldn't you? Suddenly you wouldn't have to worry about finding a bigger plot or the demo timer. What about just flat out instanced player housing where we can tailor every aspect from the size to the location of our house? Then all the FCs who want FC only wards would be happy and players would have more options than ever before. Any one of these or a combination of these would be a much much better option than limiting the number of houses someone can own. The only issue is all of these take longer and are more expensive than giving themselves more breathing room by making it so a single player can only own nine houses per server instead of sixteen. Grandfathering is a nice idea in theory but problematic in practice due to how they'd have to flag some accounts. Also the whole point of the exercise is to actually free up those extra houses to add to the new wards' worth of housing being released. It's to get as much housing back into the system as possible without actually fixing what's broken i.e. the too limited supply.
I like the timer idea but as someone pointed out to me it only stops the sale of personal housing because flippers will just start selling entire shell FCs, house and all. If a way could be figured out to stop that then yes, timers would be the best way to stop house flipping. Part of me still hopes they do it anyway, anything to cut down on the sellers.
Long and short of it is no matter how much it sucks for some folks this idea has all the earmarks of being an attractive solution to SE. Just like demos were. It's going to do the exact same thing, cause a lot of people who did nothing wrong to lose a lot of things they worked hard for and give them compensation they feel is inadequate. But just like demos it's something that probably should have been there from the beginning and it's something SE could have avoided doing entirely if they'd implemented any of the above suggested fixes instead.