Thanks for the information.
Well this is frustrating. I keep on coming back to wordpress.com and trying because it has so much to offer!
But then I run into roadblock after roadblock which seems designed to make participation difficult!
The answer to the dilemma posed in that thread is simple: let each blog decide its own default and let each follower override that default if they don't like it.
My own Posterous followers (still trying to find a place to move them) tend not to be very computer savvy. And a lot of them are in their 80s and 90s. And in many cases their vision isn't that great either.
I finally got one guy who is 92 and helping me test finally realize that he can't reply to posts by email (his replies were going nowhere) and he now uses the Comment button. But he doesn't notice the "receive email notifications" checkbox when he posts. Heck, on some WordPress blogs even I've overlooked that multiple times. It's just one more thing you have to be careful of and remember to do. (Whatever happened to "don't make me think"?).
It's just frustrating. Every time I come back really loving wordpress.com for it's incredible appearance and all its strong points, I run into these crazy hurdles which seem designed to make it difficult for my followers to engage and participate!
It reminds me of the Chompers in "Galaxy Quest." (http://www.youtube.com/watch?v=QqVqxWU-Itg)