It's kind of a stretch to even call Struts (or any similar servlet architecture) MVC. Struts is faithful to some of the principles but it is its own thing in many ways.
The history comes from fat clients with all three components in memory together. Interestingly Swing is described by Sun as a complete MVC implementation internally. In building applications we can mostly fit that whole MVC into the View component.
A couple references I found recently said MVC is obsolete, and we should think about Model Document nowadays. Might be Microsoft propoganda to justify OLE.