The description "hosted" or "not-hosted" that we use for component families can be a bit confusing. Technically ALL families ARE hosted. They are either hosted by a level, a wall, a ceiling, a floor or a face (surface of some element). When we say not-hosted or non-hosted we generally mean that a family is not specifically associated with a certain host element like a wall, ceiling, floor or face. A chair, desk and various other families across many categories are "not-hosted" though truly they ARE hosted by a Level. They can sit on the floor or are free to be above or below it by altering their Offset parameter.
I often think that it is a disservice to spend time calling them just one or the other. It seems more explicit to use a family name that describes what host is required. A family called, "MyCoolFamily-hosted.rfa" might be better called "MyCoolFamily-Face.rfa" or "MyCoolFamily-Wall.rfa" or "MyCoolFamily-Level.rfa". We could reduce it to a single letter designation. For example the families could be named "MyCoolFamily-W.rfa" or "MyCoolFamily-L.rfa". What if the file extension allowed for this subtlety so the names are not affected by it? Extensions for families could be .RFF, .RFW, .RFC, RFF... Uh oh floor and face both are "F"...so we could use S for surface instead of face?
These different placement methods also mean we have to be careful to consider what sort of hosting nature a family has before we start placing it. We have to resort to reading the family name and/or glancing at the ribbon for any placement options to figure out what the family expects us to do. It would be great if a family could be assigned to a primary placement option. For example, light fixtures usually want to attach to a face, not the vertical face option we are offered by default. Ideally we could specify the hosting priority for each family and use the ribbon only to choose an alternative when those rarer situations happen. Maybe the ideal spot for this parameter is in the Family Category and Parameters dialog, like OmniClass and other settings..
Just writing out loud...