I think that DIY ethics aside, Tony Brummel has done a hell of a job from a business standpoint. He puts out a lot of crap now (actually I wonder how much he actually has to do with it; I hear he just listens to world music now), but he has put out a lot of mid-to-late 90s records that were really influential, sonically and ideologically. Stuff like Strife, Refused, Earth Crisis, Integrity, Snapcase, etc had a lot of influence on a lot of bands out there now (unfortunately, not all of it is good influence). I remember hearing about how Strife got $25k to record "In This Defiance" and that was HUGE back in 1996 or whenever it came out, for a band of their caliber. Now for them I think its par for the course. They put Bloodlet up for a week in Electrical Audio with Steve Albini, which is about a grand per day plus tape costs, and this is when Bloodlet was making a "comeback" and they gave them a small budget because they didn't know how well it would do. Darkest Hour's last record was recorded in Sweden by the guy who did all the old Swedish death metal like At The Gates and stuff, and they're going to be doing their new record with Devin Townsend from Strapping Young Lad. I know some guys that are signed to Victory and they did their last full length with Erik Rutan from Hate Eternal/Morbid Angel at his studio in Florida.
I think what it comes down to is that Victory are shrewd businessmen. They sign the individual band members to contracts so that they can pick up options on ex-members' new bands (hence stuff like Freya, Black Maria, Streetlight Manifesto, etc). I believe they also own the publishing rights to all of their releases (they're all published by Another Victory, which is their publishing company). When you have releases that are as huge as Hatebreed's "Satisfaction Is The Death of Desire" (their biggest selling record...hundreds of thousands of copies), it brings in a lot of cash, which they can turn around and drop on their new bands.
I only really care for two current bands on Victory now, but I love a ton of their old releases, and I think its their business practices are what have allowed them to get huge. Unfortunately, they've also led to a lot of criticism from the underground community, but thats their problem, not mine.
Edit: I also believe that a major publishing company (I want to say Interscope but I'm not sure) owns something like a 49% interest in Victory now.