Along Jim's thoughts....
On the emailed versions, would it make sense to remove the "Reply to Sender" ink, and have "Private" & "Reply to Group"? And then that "Private" link would then start some other action that allows you to reply to sender?
OF COURSE NOT.
So why make the web UI more confusing than it needs to be?
That said -- I really don't care, I'll use it either way. How it would make sense or how it does not make sense. I'm ambidextrous.
I'd rather fight the good fight for many functional shortcomings that are still lacking and need Mark's attention. :-))