Just a thought ... but I happen to agree with the general principle of having a slot limit & even if it does mean that every build requires economy of slots I feel like that encourages creativity & we can all see there is no shortage of amazing house builds all done within the limits. I also see this from the ZoS point of view in terms of server resources.
But maybe an idea to compromise would be to introduce a single house plot that had a bigger slot limit. Just one. It could be a blank canvas type of property with no established buildings, but make it huge and give it a slot limit of, oh I dunno say maybe 1400 (double the current maximum)??? It could maybe even require an achievement, say something like own 5 completed 700/700 slot homes, or something like that?
Just an idea to maybe try and meet in the middle. But I don't hold out much hope given that the reason for the slot limit seems to be about server resources & that ain't changing any time soon. But I just thought of it while riding around Orsinium, thinking about how amazing it would be to have the capacity to create an entire city.