I would put it this way. Google Photos blows away Picasa Web Albums and Imgur is a better host. It was dead as Flickr will be in the next year or so sadly.

I understand that, but they broke the web by killing it.

Advertising. If it doesn't relate to advertising or have some ad revenue channel, don't expect it to stick around for long.

... but it could be. They still can serve ads there!

I was being sarcastic...