The Smashing Pumpkins singer and guitarist believes the fellow grunge legends only got back together in 2010 for financial gain.
He told PhilStar.com: ''There are those bands that are essentially coming back only to make money. Playing their old albums, and maybe somewhere in the back of their minds they're thinking there might be a future.
''When Soundgarden came back and they just played their old songs, great. I was a fan of Soundgarden, but call it for what it is. They're just out there to have one more round at the till; same with Pavement and these other bands.''
Shortly after Soundgarden reunited, bassist Ben Shepherd admitted he had fallen on hard times and technically had no home since splitting from his girlfriend and moving out of their house.
When asked where he was living, he said at the time: ''Nowhere. Literally. I've been sleeping on studio couches and at friends' houses. I'm totally broke.''
Meanwhile, Billy says he is ''not in the business'' of trading off the back catalogue of his band - of which he is the only original member - and is only interested in writing and releasing new material.
He added: ''Music has been hijacked by business, much like the American spirit has been hijacked by corporate interest.
''You have to make music for 2012. Without the young fans there is no future for Smashing Pumpkins. We can't run an oldies business. Not only is it boring, it's actually not a very good business.''