* I like short, well named methods.
* Conceptually, handling a message feels like a good, logical unit of behavior that belongs in its own method.  In my mind it's a separate thing from subscribing, and it obscurs what the `start` method does to have the details of handling messages in there.
* If we move it back, we have to use `begin/rescue`, rather than just `rescue`, and lots of rubyists (myself included) consider `begin/rescue` to be a code smell which suggests that unit of code should be extracted into its own well-named method.