Nikolai Mavrenkov already created a good description of the problem on Stack Overflow: http://stackoverflow.com/questions/36893449/textarea-placeholder-isnt-shown-in-ie-11-being-rendered-using-react

I just can confirm it breaks in IE11, but works in IE10 (and other browsers) with React v15.0.2.

var inst = this;
  ReactDOMTextarea.postMountWrapper(inst);
}
function optionPostMount() {
  var inst = this;
  ReactDOMOption.postMountWrapper(inst);
}
var setAndValidateContentChildDev = emptyFunction;
if (__DEV__) {
  setAndValidateContentChildDev = function(content) {
    var hasExistingContent = this._contentDebugID != null;
    var debugID = this._debugID;
    
    var contentDebugID = -debugID;
    if (content == null) {
      if (hasExistingContent) {
        ReactInstrumentation.debugTool.onUnmountComponent(this._contentDebugID);
      }
      this._contentDebugID = null;
      return;
    }
    validateDOMNesting(null, String(content), this, this._ancestorInfo);
    this._contentDebugID = contentDebugID;
    if (hasExistingContent) {
      ReactInstrumentation.debugTool.onBeforeUpdateComponent(contentDebugID, content);
      ReactInstrumentation.debugTool.onUpdateComponent(contentDebugID);
    } else {
      ReactInstrumentation.debugTool.onBeforeMountComponent(contentDebugID, content, debugID);
      ReactInstrumentation.debugTool.onMountComponent(contentDebugID);