I was toying with different downvoting schemes but all of them seemed flawed in a fundamental way:

You could have downvotes after a certain threshold.

You could have downvoting carry a different weight based on how much karma you have.

You could have downvotes only after a certain time has passed thus making stories with polarizing opinions not get squashed immediately but still allow for the opposition to have their voice heard.

You could have downvotes only enabled on submissions from members under a certain karma threshold.

I am sure there are many more ways to do the downvoting but I think there is a more fundamental problem with downvotes in that it creates a kind of hostile community. It might be worth having the occasional dumb story come to the front page to keep this place a civil place. Downvotes in the comment section should be reserved for a person that does not further the discussion or is overly rude to another member here.

  downvoteArticle(id) {
      for (aid in articles) {
          if (aid!=id) upvote(aid);
      }
  }

  // Find all <a> links with an id of up_* then add a downmod arrow which upvotes everything apart from this article on the page.
	
  var links = document.getElementsByTagName("a");     // Look at all links...
	
  for (var i=0;i<links.length;i++) {
    var alink = links.item(i);
    if (alink.id.substring(0,3)=="up_") {
	        // We found one...
            
    var downer = document.createElement("a");
    var img = document.createElement("img");
    img.src = "/graydown.gif";
    img.style.border = "0";
    downer.appendChild(img);
    alink.parentNode.appendChild(document.createElement("br"));
    alink.parentNode.appendChild(downer);
    downer.href = "#";
    downer.onclick = function(n) {
        return function() {
            downmod(n);
        }
    }(alink);
  }

  // Downmod by upvoting everything else...
  function downmod(node) {
    var links = document.getElementsByTagName("a");     // Look at all links...
	
    for (var i=0;i<links.length;i++) {
      var alink = links.item(i);
      if (alink.id.substring(0,3)=="up_") {
        // We found one...
        if (alink!=node) vote(alink);               // Vote for it...
      }
    }
  }

Nobody can downvote articles.

Also, TC's journalism isn't usually just MA stirring up drama. The average TC article on HN simply profiles a new startup, or service, or acquisition.