Yes, within hours of the update people were complaining the new guild quests were "impossible". I've seen nothing impossible in this list - the level 50-60 quests seem to require expert buildings at level 4 + 3x buff to be able to finish them comfortably. This means there are plenty of quests I can't do personally as my expert buildings are all only at level 1 or 2. But that's my choice.
I disagree that the buildings will "pay for themselves" if you upgrade them, but it's a game, and a non-competitive game at that, so who cares? Everyone has the choice whether or not they want to use their limited resources to upgrade the buildings which mean they are able to finish the guild quests or if they want to focus on other things.
It's like colonies - few people have the time/resources to do both adventures and colonies. So choose which one you prefer and move on.
If you're not willing to upgrade the necessary buildings, accept that you won't be able to do some of the guild quests and move on.