A while later the changes were reverted and a discussion began in the comments of the first question. My feeling was that questions should have their game-related tag, even if there are relevant sub-tags which would imply it.
They believed that having the one tag removed the need for the other, as people could still look at questions from both tags by using wildcards in their search (e.g. dwarf-fortress*).
I feel that it's unreasonable to expect an arbitrary user, while browsing tags, for example, to assume that the tag for a game wouldn't include all the questions about that game. And other games with subtags can't be wildcarded as conveniently (team-fortress-2 and tf2-pyro).
So, in essence, do people feel that a question about a specific game should always have that tag, regardless of its other tags? Should those questions in particular have the dwarf-fortress tag added back?