Drush MAMP not working
What url do you use to access this Drupal site? I notice that drush reports Site URI as http://default. This is not necessarily a problem (I have multiple working sites running on a MAMP server, and this is what they report too), but what do you get if you re-run the command with the --uri flag?

drush pmi --url=example.local

If that does make things work, you can create a drush alias file as shown below and use drush @example pmi to run commands:

$aliases['dev'] = array(
  'root' =&gt; '/path/to/example.local',
  'uri' =&gt; 'example.local',
);


For the record though, I've never needed to do this when using MAMP--but I do create virtual host records for all local development sites so that may be a factor.