Logging in should allow you to stay where you are and continue the task you're doing that required logging in.
I'm looking at a bin in a time series and want to tag or comment on it. But turns out I'm not logged in. So I click log in and do it, but then it brings me to the /secure/ dashboard page, instead of just back to the page and bin I was previously on, that I wanted to tag.
Logging in should allow you to stay where you are and continue the task you're doing that required logging in.