And maybe require a reason for the vote.
The purpose of voting is to provide a crowd-sourced ranking mechanism of questions and answers. Showing the identity of the voter may discourage honest voting based on the quality of the post and encourage the introjection of inter-personal favoritism and conflict into the voting apparatus. This has been suggested:
That was closed as a duplicate of a prior question that explains that anonymous voting is status-by-design.
A requirement for comments to accompany down votes has also been discussed ad nauseam on the network.
There is now a reminder shown to <2k users encouraging them to leave a comment if they have something helpful to say. The crowd-sourced powers-that-be on Meta.SE have determined that a requirement is not a good idea. The reasoning is well summarized in a comment there by a user who later acquired a lot of diamonds. Please contribute to the Meta.SE Q&A if you have something to add to this discussion.