From the Watchtower 1966 10/15
More than thirty-five years in advance, by help of God’s holy spirit, dedicated Bible students calculated the Gentile Times as due to expire in the early autumn of 1914, but the religious clergy of Christendom criticized them and mocked them for publishing such a Bible time schedule. But the events of 1914 silenced the critics, though they were not converted.
I'd say that there are still plenty of critics around to this day, they haven't been silenced at all.
Amongst the many problems the Watchtower faces with this teaching is the fact that there is no one living today that can testify to, or be witnesses of, whatever the orgranization thinks happened in 1914.