It didn't matter if it was Google or another company to them. What was putting them off was the thought of having to manage yet another online identity and remember the credentials. These people aren't power users. They can just about cope with doing an online search, and occasionally sign into their web mail to read and send messages. The one member who had a Google account had no problems.

I could have just emailed them the document. But it was a work in progress. I just wanted them to give it a once over.

In part this is why Google are integrating their services in the first place. Centralising signing in increases the chance of participation in their other apps.

It's a case of what you already know and anything beyond that is a barrier to entry.