In the SFBA, KQED still identifies as KQED. Its January 6+ share was 10.7, ranked #1, with a cume of 751K.
In the NYC market, WNYC was 5.2, a tie for #4, with a cume of 687K.
In Washington DC, WAMU was #1 with a 13.4 share and a cume of 620K.
So there are at least a few public stations that do alright using their own call letters as branding. If the brain trust at KPCC thinks that being cutesy with "LAist" branding has more cachet than "KPCC", the statistics (#14 with a 2.7 and 566K, in a month with a sh!t-ton of local disaster news) don't seem to bear that out.