The more I read Rich Lieberman, the more I'm convinced that he no longer has any sources. He is the equivalent of an elderly fanfic blogger but for local TV.
Lieberman doesn't see the ratings; I do. For the first two weeks of this month, KPIX was virtually tied with KGO for #2 at 6pm. I think their format and anchor changes have had a lot more of an impact than the branding change. I think adding news at 7pm, moving national news to 6:30, and putting Juliette Goodrich on the 6 and 7pm were all good ideas that made KPIX at least somewhat more competitive again. I'm not always sold on their unconventional leads and enterprise story ideas, but I suppose they're at least trying something different.
The most underperforming network O&O in that market though for sure is KNTV – literally hashmarks for their 11pm some nights. KTVU's Like It Or Not, a mindless show that costs no money to produce, regularly gets higher ratings at 11:30 than KNTV does for their 11pm news or the Tonight Show.