If you mainly work at the granularity of single apps, I could see that. I tend to use groups of apps, so without spaces I waste way too much time re-assembling my working contexts. With spaces I can just swap in a whole context, like "programming": my text editor, a terminal, and a browser open to a relevant doc all pop up as a group, arranged how I want them. And stuff not in the "programming" context disappears instead of cluttering my screen.
If I have to do this app-at-a-time, I need to bring to the foreground Terminal, MacVim, and Chrome, each with a separate hotkey press, then hide everything else. I admit this working pattern may be specific to a Unix style of "IDE" made up from multiple apps used together, though. If you just use XCode or Eclipse or something, it's already bundled into one app so maybe not an issue.
I use Terminal, Emacs, Firefox, etc., pretty much the standard setup.
The programming environment is the only bundle of apps that need to be specifically arranged for me. They pretty much always sit positioned where I want them, and I bring up other apps when I want to do other stuff, and hide them when I want to get back to programming. I never really hide my coding apps; I just bring other apps on top and hide them.
It's nice too to always know that Cmd-F1 will bring up Firefox, no matter what is going on.
But this is definitely a user preference thing, and specific to how I like working.
If I have to do this app-at-a-time, I need to bring to the foreground Terminal, MacVim, and Chrome, each with a separate hotkey press, then hide everything else. I admit this working pattern may be specific to a Unix style of "IDE" made up from multiple apps used together, though. If you just use XCode or Eclipse or something, it's already bundled into one app so maybe not an issue.