I use Mozilla when I'm at work and using Windows, Galeon at home. Both have "Personal Toolbars", which basically means a toolbar below the menu which can contain links or hierarchical menus of links. In this toolbar, I also have a hard-coded button labeled "Home" with a nice picture of a poorly built house. I understand why we had the home button way back when, but I think it's time to get rid of it now.
The personal toolbar makes the home button totally unnecessary. I can click on home, and then navigate from there, or I can click on any of the other buttons in my toolbar. I have google and dexonline.com. Then, I have menus containing Linux sites, work sites, documentation, Java sites, and news. It's actually slightly easier for me to hit the google button than to hit the home button.
So, why is it there? I think it's there for the legacy.