I'm not personally in the business of maintaining a browser.

But if I were, and I were looking to decrease cost of maintenance, "This entire rendering framework that supports a 0.02% use case" would be an outlier for chopping-block consideration. Not all corner-case features match that combination of cost-to-maintain and adoption (after, what, decades at this point?).

We wouldn't be arguing the point if the feature in question were fax machine support, right?