I'm the last person to defend google, but in the beginning a reasonable argument could be made that what they wanted was better performance of javascript and website rendering in general. Microsoft, Mozilla and Apple were the only engine developers in town. Two were the default on their OSs and Mozilla was the choice of those who made a choice. So there was no real incentive to compete on performance.
Chrome was introduced by Google with the idea of improving performance of webbrowsers in general so they could do more with web-apps. That did seem somewhat reasonable at the time.
But since Chrome became the market leader, the incentives have changed.
Google used to pay people working on Firefox, including the lead engineer at the time, Ben Goodger. They pulled them to work on Chrome. Had they wanted, they could have invested more in Firefox to improve its performance. But what they really wanted was full control over their own Web browser.
