I would guess that people miss/don't see or don't put together the Call me Ed with a blessing to address you by name?
I would gather for some it is a better safe than sorry type of issue.
As for me if I answer it got the job done no matter how I was addressed.
The "call me ed" has actually worked pat. It's not a huge deal either way really, more funny frustrating than anything else. The other guys name is quite long so it's probably worse for the responder