People using Gnome/Unity usually post their questions without bothering to mention this fact. Also, most users assume that when talking about folders or file browser we should assume they are talking about Nautilus. Many questions/answers happen without ever the DE or the file browser being mentioned, although these questions/answers are in fact Gnome/Unity/Nautilus-specific. They give an impression of generality that do not in fact posses, and may become misleading. Adding this request for users would greatly improve the clarity and usefulness of the website.
I believe that we should assume the answer needs to be about a vanilla Ubuntu. When someone is using a specific piece of software it is the questioneers responsibility to mention that fact.
That being said: this what you are asking is the function of tags and it is encouraged to use tags when opening a question. A '1 tag required and max 5 possible' is enforced when asking a question so this leaves enough room. But I do not see how AU can enforce users to use certain tags.
If you see such a question you can tag it
nautilus if it does not have that specific tag. It helps when searching for a specific issues where you know that tag is important.
Is there was a runaway trend of ambiguous questions?
I could be wrong (given my lowered presence in the past few months) but most people use what they're given. They use the defaults. If they don't they usually know enough to specify what they're using.
I know assumptions aren't great and we could pester people for all sorts of detail before they were allowed to post but, as I say, this isn't something that I've witnessed as a major issue here and I've seen a few questions in my time.
On another side of this multi-faceted coin, there is an argument that adding information for the sake of adding information only serves to water down the value of those tags.
If you make the tag relevant to what the user uses and not specifically the question, you end up with a load of junk tags. Finding questions explicitly by a desktop environment become useless.
Those tags just become meta-noise and mean nothing.