I strongly agree with you that it is not a good thing while promoting just one witness in the moderation comments and in the posts. I have never done it to place the link of the witness in my post.

But it is necessary to reach all the steemians how they can vote for the witnesses and why they should do it. I have noticed many people do not know who are the witnesses and what they do and why they should vote for them.

For this purpose there should be a proper tutorial explaining it what are the witnesses and how they contribute to the ecosystem and how the users can vote the witnesses.

In some contests and communities I have seen there is the requirement to vote for the witnesses to participate in the contest. It is a one kind of forcing the users to vote a specific witness.

As soon as I get time I will write about it to shed light on the witnesses and witness votes.