Why was old man Warner was so stuck on having a lottery every year?

The lottery is a tradition, Mr. Warner considers it a part of life. For him, cancelling the lottery would be equated to moving backwards.

Old Man Warner snorted. "Pack of crazy fools," he said. "Listening to the young folks, nothing's good enough for them. Next thing you know, they'll be wanting to go back to living in caves, nobody work any more, live hat way for a while. Used to be a saying about 'Lottery in June, corn be heavy soon.' First thing you know, we'd all be eating stewed chickweed and acorns. There's always been a lottery," he added petulantly. "Bad enough to see young Joe Summers up there joking with everybody."