Many other dates have been abandoned, e.g., 1844 (according to Adventism/Millerism which Russellism grew out of), 1894, 1925, 1975, etc.
They've put themselves in a bind with this one. Ever since the 1950's (and before), when we had our first contact with JW's, they have been preaching the significance of 1914. I can remember sitting and doing calculations from 607 BC.
After the end did not come (at least not visibly ) in 1975, there was talk about how long Adam was in the Garden of Eden before Eve was created, one of the few times a woman was significant in JW "theology."
So we are at last at the point where they don't have a date set. I think they're waiting for a new generation to set a new date. They need people like I was in the 1950's who never heard of the previous dates to hold the carrot in front of.
I am very proud of myself for realizing in the late '70's that I might have to live into old age in this world and needed job skills, a retirement plan, etc. It has made all the difference in my life.