While I understand people wanting to make resources more available to a wider audience, I don't think adding translations of question/answer to the question/answer bodies themselves is the best way to go about this:
- It creates an intimidating wall of text that people finding a question may be more likely to just ignore.
- It creates overhead for anyone updating/editing an answer to ensure the updates are consistent across both translations.
- The translation may not convey what the original author intended (if added by someone else, or if the author is not fluent in one of the languages)
- People asking questions in one language may be coming from a specific perspective (e.g. as an English speaker learning Spanish), which would not be a question generally asked in the other language, making the extra text unhelpful and essentially just clutter.
- It's generally more difficult to parse visually when everything is doubled.
I think a decent solution to people wanting to include translations of questions they think important is to add a new question/answer (and then possibly decide as a community to stop marking the 'same' question in different languages as a duplicate).
- keeps things cleaner visually and easier to read/search (especially titles)
- doesn't unnecessarily 'vandalise' people's posts (by adding a wall of text they didn't include originally)
- allows for the subtle differences in question/answer explanation from one language's perspective to another (e.g. native speaker vs learner)