I have never sold a lootspot....never needed or wanted too, I play lots of adventures and most are not single player.
If you are playing adv when guildies are not around change guild to one where people are on the same time line, or one where there are active players!
Lootpsots do many things besides encourage social playing - they give people who cant yet play those adv a chance to get experience of the map, to watch a more experienced player and their strategy and they give much needed loot to friends and guildies as well as getting them the achievement points for many adventures.
Dont try to fix what isnt broken! There are many advantages to lootspots, sold or given freely and the game would change drastically (and negatively) for many of us if the possibility of having them was removed.