What do you think the author is saying about traditions in "The Lottery" by Shirley Jackson?

Traditions should not be maintained past the point that they stop making sense. 

Sometimes traditions are continued just because they are traditions.  The point of this story is that to do something just because it is tradition is madness.  Although many traditions are harmless, some clearly are not.  The tradition of choosing one random villager to stone to death each year is not a harmless one.

The town’s against-all-common-sense adherence to tradition can be seen in to the symbolic three-legged stool and black box.  Both need to be replaced. No one ever gets around to doing it.  Why?  They have had them so long!  They are tradition.

Every year, after the lottery, Mr. Summers began talking again about a new box, but every year the subject was allowed to fade off without anything's being done. The black box grew shabbier each year: by now it was no longer completely black but splintered badly along one side to show the original wood color, and in some places faded or stained. 

The same is true of the three-legged stool.  They remain the same, or close to the same, year after year—box and stool.  The town won’t give up the box and stool, and they won’t give up the lottery.  The suggestion of giving up the lottery is scoffed at and reviled.

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…”

As far as the people of the village are concerned, things have to be as they have always been because doing anything different is too difficult to even consider.  There is a mob mentality at work here.  Tradition is so strong that the older individuals enforce it on the younger ones until they become the older ones, and it never dies out.  The author's message is that it is our responsibility to speak up against this and fight traditions that are harmful.