I think it's a lot more subtle than that. Users are always ready to jump ship, even if you don't break compatibility.
Merely introducing new functionality that competes with the old ways and shifting dev focus to it forces users to put an effort into the new ways, which irritates them, so some might not do that and might start looking around instead, depending on how deeply invested they are and how fed up they are. Others have not tried even the old ways yet and are ok with the focus on the new ways. And only few are those benefiting from the new ways. Simple strategy just can't work for everyone. There has to be a separate strategy for separate kinds of users and things that introduce competition and fragmentation must be carefully weighted.
Given all that, breaking compatibility early and often as a proposed solution seems like even worse strategy as it not just demands effort, but demands it immediately and irritates users even more, which means more users are probably going to get fed up a lot sooner.
Merely introducing new functionality that competes with the old ways and shifting dev focus to it forces users to put an effort into the new ways, which irritates them, so some might not do that and might start looking around instead, depending on how deeply invested they are and how fed up they are. Others have not tried even the old ways yet and are ok with the focus on the new ways. And only few are those benefiting from the new ways. Simple strategy just can't work for everyone. There has to be a separate strategy for separate kinds of users and things that introduce competition and fragmentation must be carefully weighted.
Given all that, breaking compatibility early and often as a proposed solution seems like even worse strategy as it not just demands effort, but demands it immediately and irritates users even more, which means more users are probably going to get fed up a lot sooner.