One of the great attributes of blogging is posting a message and having people comment on it or respond to it.
That said, there is a belief by some that reblogs should not have that same opportunity. Let me encourage you to look at a reblog just as any other post - just one written by someone other that the blogger who is posting it.
So many times I read a reblog - one that I am glad someone took the time to repost because I had missed it originally - and I am not able to thank the reposter or interact with any of the other comments. Instead I see "Comments have been disabled by the author."
It may seem that disabling comments is a compliment to the author of the original post, but it actually does everyone a disservice.
Some people will go back to the original post to leave comment (because the reblogger directs them to or they want to read other posts by that author), but that takes a little extra work and isn't often done. The reader is already at the reblog site and they'd like to leave a comment there. I have experienced several reblogs where the reblog gets more comments that the original post.
I would like to see the "Disabled Comments" function go away. It doesn't help our blogging efforts.