We are a midsized guild (around 100 members) and our guild hall is deserted for the reasons you mentioned.
I remember the first time we met in the hall at our weekly guild mission time to form groups for Guild Bounty. Everyone ported in the guild hall, but I only saw five of our members. It took around 10 secs and some chat in TS until we realized, that we were scattered over several instances of the map. We had to taxi people on one map to continue … I don’t know what I should say about that …
Pre-HoT I was really looking forward to Guild Halls. I stopped donating materials last week, as I don’t see a point in having a Guild Hall anymore.