I can't tell if you're agreeing with me or not :)

Flickr isn't about casual users, but for a while it was bloated by casual users which made it look like a site with really big potential.

"I want to make the photo storage/sharing site for all people who take photos" is a bigger proposition (and potentially more lucrative) than "I want to make the photo storage/sharing site for all pro/prosumer photographers".

For a while people were judging Flickr by the fact that it had users from both camps. Then the consumers left and Flickr looked anaemic.