The analogy of Dave's weight was directed more toward the issue of "Davesque" being a completely useless standard of weight measurement than the actual intent behind the term's usage.
There were doubtless "real-time combat RPGs" before Zelda, although the term "real-time" could be deemed less relevant given the state of gaming preceding Zelda. Titles such as the original primative Adventure and Castle Wolfenstein come to mind.
This discussion is becoming almost as farcicle as the "Why 'rock' is not a valid food group" debate...
The point, as always, is that there are a lot of games similar to Zelda in fundamentals. These games are all adventure-RPG titles. You don't see a Landstalker genre, or an Alundra genre, or a Brave Fencer Musashi genre, or a Soul Blazer genre, because we have one big genre to encompass all such games with both adventure and RPG aspects. It's the minor genre of Adventure-RPG. Even if we were to derive a genre exclusive to Zelda, there would be absolutely no practical purpose for this genre.
To elaborate, this statement is horribly misleading: "Brave Fencer Musashi is a Zelda game."
It implies that Brave Fencer Musashi is part of the Zelda category, operating as a franchise category because it now holds dual meaning. We can, however, state the following: "Brave Fencer Musashi is
like Zelda."
However, this statement does not suggest categorical inclusion, which is required of a functional genre, the genre itself being a form of category. As such, the only games that can effectively be contained within the Zelda genre would be games in the Zelda franchise, thus rendering it useless.
Of course, that's a very glib approach. Alternatively we could label the genre "Zelda-like" or "Zeldaesque." However, we still run into two problems; We suggest that there are some universally accepted and acknowledged standards by which "Zelda-like" games abide, for purpose of recognition, and we already have a valid minor genre covering this exact classification in Adventure-RPG.
It probably sounds like I'm using language semantics as a crutch, but categorical specification is entirely dependent on the level of semantic and functional distinction.