Block user to vote other answers of the questions when has provided already an answer

Question

I want to know what do you think about the possibility to block up and downvoting of other answers at the same question where you has already provided an answer. This because there are so many users that downvote answers only because in competition with its own answer.

I think that the community should decide which is the best answer and not one of the answerers. I know that one downvote can't influence the entire community but many times the first vote can influence the OP (especially in questions with low page visits).

Answer 1

Just because I answer a question doesn't mean that I have automatically accounted for all possible answers to the question.

Someone else could have posted an alternative approach, which may be better (or worse) under some situations in comparison to mine. If I think that approach is also valuable, then I'll upvote that answer. There's even a badge to encourage this behavior.

Someone else could have posted something terribly wrong. In that case, I want to ensure future visitors to the question don't walk away with an incorrect answer, one that may even be potentially dangerous. I downvote these answers.

Why should my voting be restricted just because I answered? As Martijn says, "I as other answerer am in an excellent position to judge that answer."