On Android we discourage "Is there an app for X?" questions. As you mention they are often just shopping recommendations and exclude non-app solutions for, usually, no good reason.
We try to rewrite the "good" ones in "How can I do X?" questions. The answer may be an app, but that's up to the answerer, and allows other solutions to be posted. It avoids the problems of shopping recs and fits the format outlined in the FAQ very well.
Some questions just can't be rewritten like that though, and we try not to close most of those on Android if they're clear and have detailed criteria. You can't use anything but an app as a file browser, for example.
In the case of the Pandora question, it isn't clear to me whether a mobile website for streaming or something like that would work just as well. If the question stays open, it should be broadened beyond apps or clarify the criteria.