After login you're taken to the default dashboard which (usually I guess?) is the dashboard of the top hierarchy for your account. Since one size does not fit all, my suggestion is to make the starting page (your preferred dashboard) selectable in the user preferences. That is, if you like to have "My dashboard" (which you can customize) as the first page after login, you can do so. After all, people expect to be able to customize their dashboard, and starting off on the site dashboard does not allow you to. This creates some confusion among our users.

Bottom line - you should be able to select "My dashboard" as your default starting page.