Wrong. The Supreme Court summarily affirmed Baker. A dismissal for "want of a substantial question" is NOT simply a denial of cert. "[A] dismissal by the Supreme Court is an adjudication on the merits. . . a lower federal court must consider itself bound by the dismissal when a similar challenge comes before it."
"[D]ismissals for want of a substantial federal question without doubt reject the specific challenges presented in the statement of jurisdiction". Mandel v. Bradley, 432 U.S. 173, 176 (1977).
Summary decisions "prevent lower courts from coming to opposite conclusions on the precise issues presented and necessarily decided by those actions." Mandel v. Bradley, 432 U.S. 173, 176 (1977)
Baker is the law of the Land, not just California. So again, do you agree that since it is the law, Vaughn Walker is obliged to follow it? (Since the jurisdictional statement in Baker specifically included both Due Process and Equal Protection grounds.)
Varying circuits have applied Baker in varying ways. It may be the law of the land, by that law is remarkably under-defined. Until the Supreme rules more definitively, it's impossible to predict what the "law of the land" will be.