It think the term "street-friendly camber" has to be qualified by a person's goals.
I do 2 to 3 track events a month and I want to keep the car as stock as possible. So, my main goal is to strike a good balance between street and track wear and to have a neutral handling car. The square setup alone helps with both goals. However, in my experience (12 yrs), anything less than -2 up front will destroy the outsides of the fronts in one or two track events.
Even with -2.2, I don't get even wear at the track. Life of the tires will still be determined by the outside tire wear, so, inside tire wear if of not importance to me. I've got well over 7000 miles and 9 track days and the tires need to be replaced due to outside wear. I rotated the tires about every two track days (crosswise since they are asymmetrical RE11s).
I probably could go with -2.5 or more and achieve a more equal balance between inside and outside tire wear. However, I decided to switch from RE11s to AD08s since the latter is a symmetrical tread tire which allows me to swap the tires on the wheels to get even more life out of them since the insides are in great shape on the RE11s.
For someone that does not track the car very often, then, yes, less than -2 is more street friendly.
'11 E90, Cantrell brake ducts, Apex 18x10 ARC-8, 265/35 PSS, RS19 pads, -2.2 camber, CMS Lap Timer Pro