Tumblr is not a blogging platform, it is a social network. Tumblr revolves around the dashboard, it's much more Twitter than it is Wordpress.
I have 12 blogs on Tumblr (and counting), almost all of which I post to frequently - and the only thing I ever use the dashboard for is to make those posts. The only social action I have ever taken was to reblog a recent post I found on reddit, mostly just to see what would happen.