I have noticed that sometimes answers are downvoted in order to cause the automatic deletion of a question by the community user. In particular, there are closed questions with $1$-point answers - when the answer(s) are downvoted to $0$, they are then eligible for automatic deletion, which can only be undone by the moderators.
This was briefly discussed in a comment thread on a related meta question, but I would like to know what the community's feeling on this issue is in a more general sense. The vote total on Bill Dubuque's comment opposing this practice would seem to indicate that there are numerous people who disagree with this.
Personally, I believe that answers which are on-topic and mathematically valid should never be downvoted, regardless of the question quality; this does have the (perhaps unfortunate) side effect of preventing low-quality questions from being deleted.
Edited, $15$ hours after the original post; for the sake of noting the vote counts before this substantial change, the question is currently at $+5/-1$. Note that all the answers (except for Thomas's answer) were received before the substantial change to the question, and responded to the abstract issue.
This question was motivated by the actions of a single user, who is now making a large-scale effort to remove old questions that do not meet various quality standards. For example, all of these questions had close votes initiated by this user, and were subsequently deleted automatically due to $0$-score answers with $1$ upvote and $1$ downvote:
and so on; other examples are 501467, 500197, 499054, 498085, 497807, 497583, 495832, 495732 and 495710, all of which were removed during the latest round of autodeletions. I am breaching the usual convention of no-naming on meta because the user has already given an answer to this question, stating that this is an action they regularly carry out; see also here.
I consider this behaviour to be abusive and gaming the automated deletion process in order to remove large amounts of content from the site. It circumvents the fact that the privilege of casting deletion votes is limited to the most experienced users of the site, and I think that many of the close-voters on these questions (myself included) would have seriously reconsidered the votes if they knew the ultimate fate of these answers.
Edit, part $2$, at the suggestion of This is much healthier. As Healthier points out in a comment below, a network-wide update means that these deletions are no longer irreversible - the posts automatically deleted by the Community user can be undeleted by non-moderator users. Although I feel this is a step in the right direction, I don't believe that this substantially changes any of the points I've made in this question; it would still take a large-scale coordinated effort by users who can cast undelete votes in order to counter the voting actions of one single user. Considering the hundreds of questions involved here, I do not believe this to be feasible.