[continuational]

Firefox was also clearly a better user experience at the time, which made it much easier to convince people to switch.

I switched back to Firefox a while ago for ideological reasons, but the majority of people are not going to switch to something that is more or less the same, just without their bookmarks, passwords and history.

[mostlysimilar]

All major browsers have a dead-simple import tool, and they even asks you if you want to do it the first time you open them.

[fartcannon]

Yeah, plus people use whatever they think is the best. If you're an authority on the subject, tell them.