Google doesn't seem to like RSS/Atom much any more (there's still no feeds from G+). But Is there an RSS/Atom feed for Google Photos? And preferably one that's as easy to use and consume as Flickr's that has content that contains the html to show the photo imgs.

And if not, why not?

Feeds are the simplest, lowest common denominator for getting content out of Photos and into other systems. eg using dlvr.it or iftt to auto-post to other systems. Or to fill a sidebar widget in a personal blog.

eg. 
https://www.flickr.com/services/feeds/photos_public.gne?