Location to install plugins on OS X is basically inaccessible to the user.
This issue was created automatically from an original Mantis Issue. Further discussion may take place here.
Currently ParaView looks for plugins in ParaView.app/Contents/plugins which is not conducive to development and end user use.
I have added a few more paths that ParaView will look for plugins:
ParaView.app/Contents/plugins a folder named "plugins" that is located at the same level as ParaView.app ~/Library/Application Support/ParaView/ParaView3.3/Plugins
This makes the user experience better on OS X.
Patch is Attached