Serve also the "bulk surveillance" adversary model
In the design document paragraph 6 "History records and other on-disk information" from "3. Adversary Model" make Tor Browser an instrument dedicated to help against targeted surveillance, not primarily focused on combating bulk surveillance.
In practice this means that when you install Tor Browser on an average mainstream user's laptop she will try it once or twice, then ask for a "normal" web browser. One that does all those convenient things like complete history, fill out forms, restore tabs after a computer crash and so on. A browser that doesn't do that simply appears broken.
So the difference in threat model is to accept that mainstream users would like to enjoy Tor Browser for its anonymization, reduced tracking/fingerprinting and improved Javascript security but they are not paranoid about the safety of their own computer, thus they don't enable Private Browsing all the time and prefer to enjoy the convenience of a browser that helps them do their everyday work.
In order to address bulk surveillance, Tor Browser needs to become an acceptable choice for mainstream users and work on its market share. This IMHO is reasonable because none of the existing mainstream browsers fill that role, they all support the surveillance apparatus, whereas for Tor Browser it just means a few more things to improve/make configurable here and there to become the best possible browser for most netizens, not just Torrorists.
This task ticket serves to let TBB developers choose the priority this type of usage should have and to collect the bug/enhancement reports specifically related to improving the user experience of those who choose to disable private browsing mode.
Trac:
Username: vynX