I'm not a programmer (nor do I play one on TV...) but I do consider myself a "homebrewer" and I'm particularly proud of that label. As far as I know, the computer use of the term originated with the Homebrew Computer Club, which just about any nerd worth his salt* would've given his eye teeth* to have been a part of. To me it's not a mark of denigration at all.
I consider it a privilege to be associated with the programmers that have graciously asked me to work on their games. And it's always done for fun. The fun of creating a game for others to enjoy. The fun of showing off a newly discovered programming trick. The fun of realizing a decades-old dream of creating your own game. The fun of being part of this community. The fun of just making something really cool for the sake of doing it. The documentary "Triumph of the Nerds" referred to it as "Impressing Their Friends".
As for professionalism, the programmers I've worked with absolutely obsess over their games. Refining, debugging and honing every last bit to make them the best they can possibly be. And I can speak to Albert's own obsession with producing absolutely first-rate, professional packaging (mainly because of all of the times I've had to go back and fix things after they've gone off to be printed ). And FWIW, AtariAge presently has more 2600 titles than any single publisher ever had, except Atari. And AtariAge is gaining on 'em.
As for Audacity, I can see why they wouldn't consider themselves as homebrewers: they programmed 2600 games for a living back-in-the-day. That was their profession, and even though it isn't anymore, it would probably seem weird to them to revisit that part of their careers and rebrand what they're doing as something different. I will say though, that even though they're a "real company", by repeatedly distancing themselves as being "professional" and not hombrewers, they're implying that all homebrews are not professional. And while some are not, I take issue with that sort of blanket generalization. After all, being a "real company" does not guarantee high quality either. Apollo was a real company. Even Mythicon was a real company. Effectively though, they're just as homebrew-y as AtarAge. They even say as much at 10:10 in this interview, where they talk about how each game is handmade by "volunteer manufacturers". Wouldn't a "real company" pay for that labor?
To me, whether it's "independent developer", "homebrewer", "third-party programmer", a "real company" or whatever, when it comes to making games for a niche, hobbyist, fan community, it's all the same. It's just semantics until you've got a spot in the aisle at WalMart. In the end, it's really the games that will tell the tale. So far, in this new endeavor, they've made one.
* How about that? Two completely antiquated idioms in one sentence!