Allow me to speak from the mindset of a consumer. The average consumer doesn't care about Firefox's data storage policies or how much they cooperate with the government. They care that things just work and are fast enough. For me, the convenience of Google Chrome comes from the fact that it is tightly integrated with all of Google services. I can use one Google account to log into my browser, access my email, set up a calendar, etc. Sure, Firefox can do syncing too, I just prefer using one company that does it all rather than two that do half.

Also, unrelated, I think Firefox spent too long copying Google Chrome's interface and now they are playing catch up.

Regardless, Firefox usage continues to decline month after month. I think they've lost the general consumer appeal.