This is a welcome plugin, and I'll most likely be implementing it on my sites once I've check it over, but what's with the confrontational attitude from the Roots developers?

"The WordPress core team simply doesn’t care enough about this issue to solve a UX problem which would make every WordPress site, and its users, more secure."

Where on the linked Trac ticket is there any suggestion that the core team, or anyone else for that matter, doesn't care about this issue? There's recent and ongoing discussion from multiple lead developers who quite clearly state their support for implementing bcrypt, but that WordPress cannot switch to bcrypt without first addressing the UX concern of users who migrate sites between servers that do or do not support it.

We're all in this together. Suggesting that the core team does not care about an issue is not productive. Let's fix the UX concerns and then move this issue forward.