Why is Yahoo not even leaving a read only option for this page?

"the Yahoo Answers website will be in read-only mode"

i'm sure you can still find your fill of historical content online; where do you think we get the answers from  :)    we look it up if we don't know

It costs.money to leave it up. Why should they fund a dead site

Because they don't choose to do so, and there's a whole lot of garbage posts too. There's little to no "historic value" in leaving up questions that people can find in searches on their own (which is a lot of what was asked here, by people unable or unwilling to do their own searches).