I think it depends on the person. I also prefer one monitor. I'd rather have a big monitor than several screens. Also, I never really have more than one window open at a time. I don't mind switching between windows. But some of my coworkers swear by multiple screens and one app per screen.

I think it's the same with tab management in the browser. I average 4-5 tabs open at a time, never really going above 10. But many of my friends are rolling with 80+ tabs at a time.