Arguments in favor of removing it:
- As a tag, it's pretty vague. It's sort of like tagging your questions with 'not-bitcoin'.
- If it's supposed to go on all non-bitcoin questions, then that's not being done right now.
Argument against: Some questions, like this one are actually about alternative blockchains in general. In that context, it doesn't really make sense to remove the tag.
My opinion: Remove the tag on questions that have a more specific tag. However, when someone wants to ask about bitcoin alternatives in general, leave the 'alternatives' tag.
For example: If I'm asking about how Litecoin's hashing algorithm works, then that shouldn't be tagged alternatives. However, if I'm asking for an overview of different proof-of-work schemes used by alternate blockchains, then that ought to be tagged alternatives or alternative-blockchains
