Do you mean the limited-time Crowns-only housing which is located in the event zones?
They would probably never have all of them on sale at the same time-- at least, I don't remember ever seeing more than one limited-time Crowns-only housing offered in the Crown Store at any given time.
But it does seem like a lost opportunity.
Maybe they could have offered them one after the other, each one being in the store for several days to a week before being replaced with the next one?
I think the OP has a very good idea here. If ZOS is going to do zone-based events, then making the Crown Store homes in those zones available during the event seems like a no-brainer. Maybe tack on a small discount to incentivize them (there are six in the Daedric War zones), but one would think that having a zone's houses available while players are running around in those zones anyway might be a good way to generate some impluse buying.
I'm fresh out of outrage, but I could muster up some amused annoyance if required.
If I recall correctly, Pariah's Pinnacle was made available during the Orsinium Celebration event and then again during the combined Year One Celebration event (at a reduced price as well).
So they have had these crownstore homes availabled during Zone Celebrations in the past.