Comments - enable for non-reg users

My reasoning is that I post something to share, and the general public to see. But AFAIK, the only way to comment is to become a BK member. 2 issues arise here, 1) BK is till invite only, right? & more importantly, 2) if things are shared publicly, like on a blog, users may want to enable viewers to comment regardless of their BK registrations status. Like commenting on a blog vs. registering for that blog. E.G. I sent a pic of a significant event to my 200 person office, but none of them could comment on it inline on the page. This was frustrating. I like BK, and I am working to wrangle around UI confusions and generally good evolution - thanks for the wonderful service. Am I working from some fundamental misunderstanding of the service by wanting to enable discussions on my posts?