One of the major reasons I started playing World of Warcraft again was a lot of positive buzz about Warlords of Draenor, and in particular Garrisons. I've enjoyed the Garrison, but it is in many ways flawed and I've been exploiting these flaws rather severely.
When I quit all those years ago the "minimum wage" of WoW was daily quests. Each day your average player could complete 25 of these, generally taking an hour or so, for a reasonable amount of gold. Savvy players could make far more gold by manipulating the Auction House, selling dungeon/raid runs, or crafting/farming rare items to sell, but daily quests were the primary source of gold income for the vast majority of players.
One of the more interesting aspects of the Garrison is that it replaces daily quests. Rather than require players to spend more so much time each day completing repetitive quests to secure their gold income, players can now send followers on missions that yield gold and other rewards. This takes mere minutes, and thus allows players to engage in the activities they actually enjoy.
This change is a fairly smart one, as much of WoW's original player base is aging, having kids, and losing hours of time they once spent player WoW to other tasks, goals, and needs. However, it has some unintended side effects.
With the time commitment for this income essentially non-existent, securing it on every character a player has is now fairly trivial. The time commitment, and repetitiveness, of daily quests made trying to complete them on alts prohibitive; few people had the time or patience to spend 10 hours a day on daily quests. Now that the same income can be achieved in less than a minute per character altoholics like myself are exploiting this quality of life improvement like crazy.
This only became worse when Blizzard recently introduced a follower trait which doubles gold rewards from missions they complete. Doubling one Garrison's gold income isn't a big deal, but doubling 11 Garrisons' gold income becomes silly quickly.
There are other aspects of Garrison design which obviously did not account for multiple characters. Each Garrison comes with a mine and an herb garden that fill with resources daily, but with just a couple of alts you get more resources than you can possibly ever use. Even more casual altoholics can become wholly self-sufficient, never needing to actually leave their Garrison at all save for dungeons and raids.
Garrisons are fun. I enjoy sending my followers out on missions and I enjoy the rewards I receive, but they were never designed with alts in mind. It's an oversight I expect Blizzard won't be able to correct until the next expansion, but in the meantime I'll enjoy these Halcyon days.