I would like to specify what "worthy guildhouse" means to me
1. a lot of slots and free space for crafting stations - must be notable house only
2. good entrance point -no obstacles, corridors, walls etc and prefereably something visible which makes orientation easy (boat on Grand Topal for example)
3. one dimensional house - no complex map with multiple loading screens
4. prefereably plain terrain, no stairs, no rocks, no holes, no unmovable things near entrance point
5. decent look no Coldharbor design !!!!!
6. a lot of good light, prefereably all the day long
7. prefereably high invisible ceiling and distant invisibe walls
8. a lot of water as it can't be added by any means
9. should be available all the time, not once per two years as the vast majority of limited houses
10. must be designed that it doesn't scream "this house is not very good" (majority of houses usable as guildhouses has something ugly and disturbing which makes them less attractive, hence the players are buying more and more houses to compensate the problem)
If you look at it, The Grand Topal is probably the only house having at least majority of the features.
But even very limited Grand Topal has it's own problems because you have to place around 60 platforms into the sea to make it worthy guildhouse and these slots are desperatelly needed for something else.
Coldharbor would be OK if it is not absolutely ugly which can't be fixed without spending tons of slots.
The most issues is with entrance area because ZOS likes to create new houses multidimensional with small and unusable entrance.
Some exceptions exist for example Doomchar would be usable if it is not nearly as ugly as Coldharbor. But COldharbor has plain terrain and Doomchar has rough terrain and it means a lot of platforms (and additional slots - the same issue as Grand Topal) because crafting stations must placed on something solid and geometrically perfect.
So the question is:
as the number of crafting stations is increasing and the problem with slots is worsening would it be really so big problem for ZOS to design at least one new decent guildhouse instead of tons of unusable things? SOmething that doesn't need to spent around 60 slots to make a room for crafting stations and doesnt look like a scrapyard after a nuclear war ?