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.

'<%s> tried to unmount. Because of cross-browser quirks it is ' +
          'impossible to unmount some top-level components (eg <html>, ' +
          '<head>, and <body>) reliably and efficiently. To fix this, have a ' +
          'single top-level component that never unmounts render these ' +
          'elements.',
          this._tag
        );
        break;
    }
    this.unmountChildren(safely, skipLifecycle);
    ReactDOMComponentTree.uncacheNode(this);
    EventPluginHub.deleteAllListeners(this);
    this._rootNodeID = 0;
    this._domID = 0;
    this._wrapperState = null;
    if (__DEV__) {
      setAndValidateContentChildDev.call(this, null);
    }
  },
  getPublicInstance: function() {
    return getNode(this);
  },
};
Object.assign(
  ReactDOMComponent.prototype,
  ReactDOMComponent.Mixin,
  ReactMultiChild
);
module.exports = ReactDOMComponent;