That's a good question. In strictly financial terms, it would be hard to quantify, because you wind up talking terms of subjective measures like "user good will" and "brand perception" etc. There might not, in fact, even be a strictly financial argument that favors doing this.
I still think it's the Right Thing To Do though. I know the old saw about "don't be evil" is probably over quoted and that it's just a tagline and not a binding legal agreement, but for a company like Google, given their history and reputation, this feels wrong.
Standards are a mechanism that allow new and innovative market entrants to compete with established giants.
Now that google are an established giant, there probably isn't much financial incentive for them.
You're right that it's the right thing to do though - it leads to more competition, better services for consumers and faster innovation, enriching humanity.
In the past, google knew that having a healthy web platform was more important to their long term profits than huge numbers of tightly tied in users. That no longer seems to be the way they see things.
I still think it's the Right Thing To Do though. I know the old saw about "don't be evil" is probably over quoted and that it's just a tagline and not a binding legal agreement, but for a company like Google, given their history and reputation, this feels wrong.