After looking through my core set cards, I found myself wondering what exactly is the point of playing such locations as attachments to a house card. Is there some bonus to it that I don't yet understand?

It depends on what you expect to encounter. Against decks that have strong attachment control, you're safer playing them as a location. Against decks that have strong location control, you're safer playing them as an attachment.

Kingsguard said:

The benefit is that it is unaffected by negative effects that affect locations. The downside is that it is subject to negative effects that affect attachments.

Ah, I see. Thanks.