I agree with you if done right, email marketing is very effective, and can build a very responsive community.
It is sad as I have joined and unsubscribed to a lot of email lists over the years, and too many spams their subscribers offering no value.
Yes, if done right I notice even those mailing lists I stick with will get spammy sometimes. A mailing list should be treated the same as a blogging platform it is all about giving great content. Any sales should be 2nd or even further down the importance level.