grammar - "There were lots to do" vs "There was lots to do...": is the backward existential still used?

I read in a book:

There were lots to do on the farm: feeding the hens, collecting the eggs, going on a hay ride, visiting the ducks.

To me it seemed odd, that it should have been "There was lots to do"—but it was explained that this was the backward existential and was therefore correct. This seemed outmoded to me.

My question is: "There were lots to do" vs "There was lots to do...": is the backward existential still used?

NOTE:
I believe this is not a duplicate of this or this as we're asking a question about the general usage of the backward existential in a particular situation.

Answer

In this specific case, some might see it as a backwards existential problem, but looking at it from a broader perspective, it can simply be a problem of whether you want to acknowledge the plural.

To clarify, lots is plural. Some might take that literally and use were before it, but others might see this as a kind of colloquialism or "just something we always say," so plurality is overlooked and was is used.