I think I get your point. Since in django people include it explicitly they do not mind following the instructions, if we include implicitly then we are forcing user to run syncdb or face the 500, which user wont like. 

I just looked at the source code of debug toolbar and it seems we do not have to put it in installed apps settings. There are no models, and no templatetags, just a custom management command. People who want the command can configure INSTALLED_APPS manually. 

No?