For example, I searched for banana boat, thinking of the song. "Song" was not one of the tags offered. Nor "day-o", nor Belafonte. But I did get "formation of an attorney-client relationship" and "High levels of benzene". It looks like both of those have a high number of other, related tags, like someone pulled a bunch of tags from one or two web pages. I see what looks like a cluster of "sun & sunscreen related" good, but should only be one or two tags. "Food", also good. Also should be just one or two tags. "Law", shouldn't be there at all, unless there is some POPULAR legal aspect of banana boats I'm not aware of, and "toxic chemicals", should be one or two at most, and probably should not be there at all.
I think something is wrong with your clustering. You are not getting the right clusters, and you are going too deep into the clusters you have.
FYI: The song is the first video hit on google, and the top of the second page of general results.
Tried star trek. Still too many tags. Tags are more related, but there are ones that clearly aren't important enough in relation to warrant being a top tag, like "former Viacom", "smaller population countries", "notable exceptions", "extreme example", "generic rule of thumb".
Keep refining! :-)