Google's value is in its comprehensiveness. Both the marginal value and cost to maintain a single piece of content in their index is extremely close to zero.

> If it had zero value why would Google be interested in it?

Again, value is subjective. Even if you think it has zero value, even if every engineer at Google thinks it has zero value, it might have value to someone out there. If nothing else, it could be a part of a corpus linguistics study.