I quite liked garrisons. They fed into the other aspects of the game rather nicely and when I pick up a game I want to actually play it and work towards greater goals. My main complaint was the lack of customisation and that the Alliance aesthetics were far more appealing than what the Horde ended up being stuck with.

As for what could be done in order to make Island Sanctuary more engaging? There could be treasure that washes ashore from time to time and deep in the recently added cave there could be enemies to fight for interesting rewards.