I have been reading over these posts, and I see a lot of truth and a lot of garbage on both sides of the fence. So, let's see if we can do some sanity checking here...
First, let's get this out of the way, as it is DF WILL be stolen. It is not a question of if, it is a question of when, and that is if NOTHING changes. I looked at the DwarvesSH sight and it is quite obvious that project is going to die a horribly ugly death, but it only serves to prove the OPs point that Toady Keeping the cards close to his chest solves nothing. Regardless of whether Toady is closed source, open source, a AAA Publishing Company or the Lone Ranger, if someone wants his code, they will get it. Pure and simple. That is not even an argument.
That also eliminates a few other arguments, such as forking. Footkerchief, I hate to break it to you, but your argument on this has already been shot in the foot. Forks have cropped up and failed already. They will crop up again and fail. And they will keep doing this until someone succeeds BECAUSE THE SOURCE IS ALREADY OUT THERE. It may not be pretty, and it may not be the latest and greatest that is available, but its roots are already out there. The only way to stop that is to have a dev cycle that is rapid enough to leave them choking on your bits wondering how the hell you did it, and to have a game that is so blindingly awesome that creates its own gravity, drawing "potential fans" in.
I also agree with the OP that the dev cycle will continue to slow until it simply stops. No matter how much resolve Toady shows, that is inevitable. I have nothing but respect and admiration for the man, but I have not succumbed to hero worship yet. As a game designer, I can still look at this project objectively and see with a fair amount of certainty what the future will be for it if the path doesn't change.
Toady doesn't want to work with other people. Wonderful!! But ultimately, HE ALREADY IS!! So that argument loses all weight. He works with this community. He works with his alpha testers. He works with the people doing the DF Talks. He works with the large volume of people submitting feedback and bug reports. He works with the media when he does an interview. All this crap about 'Toady is an island' and 'DF is Toady's Baby' is garbage to begin with. Toady quit being an island the instant he took the first suggestion or criticism or bug report regarding DF. And DF quit being 'his baby' the second he took a dollar from anyone as a contribution. Toady is the driving force and retains creative control. Super, but all that other is a load of forgotten beast extract.
Toady is a self-employed entrepreneur. Toady is selling a product, even if only via donations. Telling yourself and others anything else is a lie. Toady gives out free samples of his product in order to generate enough interest that not only will more people play, but more people will donate. The only difference between his model and that of publishers like Zynga is that Zynga gives you in game items for your 'donations' and Toady gives you art. And even that is not 100% true now since he added creatures to the game in exchange for donations.
DF is Toady's BUSINESS. You say as much when you call it his livelihood. If this is his life's work; if this is his livelihood; and if this is his business, then in his head it has to become larger than himself and his own preferences or personal grievances about working with others. That is not a criticism against Toady, it is just the way the world works.
Not only that, but from a more human and objective standpoint, no one in their right mind would expect that the contributions will remain at this same level or better for the rest of Toady's life. That means that either Toady has to sacrifice his life on the altar of DF, or he will eventually have to find another means to support his life.(Wife/Kids/Cars/House/etc) They may not be that important to him at the moment, but to expect that he will never meet someone and get that familiar urge to settle with someone is as ludicrous as it is shortsighted. To expect that this person or change in lifestyle, whomever and whatever it may be, will not only support the growing expenses but still willingly allow Toady to sacrifice all of his time to DF is equally ludicrous and shortsighted.
By identifying these future problems and setting things up in such a way that he is prepared not only financially, but time wise, Toady will be protecting his 'life's work' and his livelihood while opening up the possibility for him to have a life outside of DF.
I guess to wrap this up, I will say this. I have great respect and admiration for Toady and his ability as a one game designer to another. However, he has made the choice to step into the realm of being a professional game designer, and that means he has to be objective and critical, not only about his game and his vision, but about the methodologies he uses to make them a reality. A great game is not about the code, or the designer, it is about the players. Players are a notoriously fickle bunch, and things like long dev cycles, bugs, poor UI's, and such will eventually take them elsewhere, no matter how much they may love the game.
Regards,
Tony