Sharepoint - Permanently add persons to a group calendar view

[EDIT] I didn't spot that you were looking for an "official" answer - if you want that I suggest posing the question to Microsoft. One would hope this gets fixed in vNext.

AFAIK this is expected behaviour.

Obviously this is inadequate as (like you say) it effectively defeats the purpose of the Web part.

This has been discussed on numerous forums but the closest item I found to a fix is this: http://zepeda-mcmillan.blogspot.com/2011/03/displaying-default-resources-on-group.html

The workaround involves using fiddler (a Web debugging proxy) to grab the ECMAScript used to add the appropriate resources to the calendar, uploading the script and referencing it in the appropriate page.

Whilst far from ideal it's a decent blog post and a relatively straightforward solution assuming the resource list wont change too often.