No they're aware, just probably do not think the cost:benefit ratio is worth it. Especially after SW: The Force Unleashed games and now ToR, they would not want to saturate the market with SW titles, the popularity, at least in my opinion, is not enough to support so many titles back to back especially being on the same platform and so similar in game play.
Plus, KOTOR's engine and system are dated. I'm not a game developer and I have no experience in programming but I do not think that there is a game engine today that would fit KOTOR (at least, the style that we know and love) without major revamp or just a whole new engine from scratch. BioWare for instance, besides ToR has been mainly working on Mass Effect and its sequels. I love those games, but the combat would not fit KOTOR. Or at least, I doubt so.
But, even with all those considerations (plus many others that have been discussed here and elsewhere) I think you answered your own question. If TOR gets a large fanbase, which it does seem to have, why bother with anything else but expansions and DLC for TOR? That is where they can make money, and at the end of the day that is why games are produced and developed. Even if one wanted to argue for the sake of story continuity, for all intents and purposes they already did that by including mentioning both Revan and the Exile in TOR.