To get it out of the way upfront, minecraft-xbox isn't of the format game-platform: the game in question is Minecraft: Xbox 360 Edition. Due to a number of reasons, it diverges quite heavily from the PC Minecraft, and should be considered a different game.
Think the difference between a game like, say Call of Duty and Call of Duty: Modern Warfare, or Command & Conquer and Command & Conquer: Red Alert: similar gameplay, same franchise, different games.
So the existence of minecraft-xbox does not justify something like skyrim-xbox, as both Skyrim for PC and Skyrim for Xbox 360 are the exact same game.
But it's really about whether minecraft is appropriate on minecraft-xbox questions.
The weakest argument for the inclusion of both tags is:
People who are interested in Minecraft are also necessarily interested in Minecraft: Xbox 360 Edition questions, so it should be tagged with both.
Which you presented as:
[Minecraft] is a much more popular tag (1269 vs 7), so will give the [Minecraft-xbox] questions better visibility when searching. Removing the more popular tag bascially "orphans" these questions.
Even if this were remotely true, this isn't how tags work on Stack Exchange: we tag questions based on what they are about, not based on what the asker thinks will attract the largest audience. If we did that, every question would be tagged skyrim or diablo-3.
Instead, the "official" workflow for people who are interested in all things Minecraft is to create a tag wildcard in their interesting tags: something like [minecraft*].
Then, there's the second argument you presented, which was:
Several of the [Minecraft-xbox] questions are asking about a problem that ended up being a bug or limitation specific to the XBox version. This is only apparent in retrospect, and isn't necessarily obvious to the asker of the original question, or to future searchers. The [minecraft] tag should stay to aid those future searchers who don't know this will end up being an issue specific to only one platform.
I'm not sympathetic to the "but the asker doesn't know beforehand" argument at all: Stack Exchange is designed to handle situations where the asker doesn't know everything about their situation. For one, the community can easily revise a post to ensure the asker is using the correct tags.
Secondly, the hyphens in tags are ignored in search engines: if a question was tagged incorrectly as minecraft-xbox when it's really talking about the original version Minecraft, it will still show up in search results for "minecraft" because search engines don't see "minecraft-xbox" as one word: they see "minecraft xbox".
Finally, the games have two different code bases and are about 1.5 years apart in terms of features. It's exceedingly unlikely a person will misidentify a question—much less a bug—about original Minecraft mechanics as being Xbox 360-only. An asker asking about a bug when they're playing Minecraft: Xbox 360 Edition is almost certainly not going to go wrong by tagging their question minecraft-xbox.
The only related issue we'd have to worry about are people mis-tagging Minecraft: Xbox 360 Edition questions as simply minecraft, but again, that's why we have community editing.
Another argument is:
Because there are so many versions of Minecraft out there now, minecraft should be used as a synonym for minecraft-series. minecraft/minecraft-series should only be used if the question is about the game series, or about something that applies to all Minecraft editions.
I'm sympathetic to this argument, but there are a number of practical issues that need to be resolved:
- What happens to the hundreds of questions that are, in fact, about the PC Minecraft? Should they get renamed to minecraft-pc or minecraft-original-recipe?
- How do we deal with the fact that people have been misusing the minecraft tag for all the Minecraft games, which would prevent a simple rename?
- Furthermore, how to do we discourage people from just using minecraft?
- What questions count as minecraft-series questions? Given how divergent all the editions of Minecraft are and how quickly the game iterates, what could reasonably be considered general enough to apply to all Minecraft editions?
Tha't not to say these questions are unresolvable, but deserve a lot more discussion than a passing mention in the comments.
I think in the long term, it might make sense to disambiguate the minecraft tag into minecraft-series and the edition tags, but for now:
- Use minecraft if your question applies to the original version of Minecraft.
- Use minecraft-xbox if your question applies to Minecraft: Xbox 360 Edition.
- Use both tags if your question applies to both games (should be rare).
[minecraft]and[xbox-360]? It's a minecraft question, that is specific to the xbox[minecraft]and[minecraft-xbox], for a similar reason to tag a question[diablo-3]and[diablo-3-monk]: The question may be of interest to people browsing/searching either tag.