Successful or even good sandboxes are very dependent on who's making it.
The problem is, or rather the reason why sandboxes (as a whole, regardless of engine) are so disliked is because devs often use it not as a game mechanic, but as a clickfest to make the game seem longer. Pile that onto generally bad user interfaces, bad/unclear/no directions, typically minimal content for a fair stretch, and the reason for it's (mostly) consensus dislike of sandbox games becomes fairly clear. Games like Summertime Saga and Harem Hotel are really the few exceptions, and in the former's case, its popularity more so roots in it's ability to actually feel like a game while also appealing to a multitude of both popular and somewhat niche fetishes.