What happened to competitive primaries?

Proponents of the open primary and citizens redistricting political districts had hoped the two changes would result in more competitive races.
For the last 10 years, with districts designed to protect the incumbents, only the primary election mattered because seats rarely changed parties in the general election.
The surprise, now that filing for the June primary has closed, is how many East Bay seats will be uncontested in June with the incumbents getting a free pass.
For instance, four of the six seats on the boards of supervisors of Alameda and Contra Costa counties will see the incumbents re-elected without a challenge.
In Alameda County, both Keith Carson and Scott Haggerty are running unopposed. It will be Carson’s sixth term, while Haggerty will be unopposed again and will start his fifth term in January. Nate Miley, who now represents Pleasanton, is being challenged by Tojo Thomas, a deputy probation officer.
In Contra Costa County, redistricting shifted Supervisor Mary Piepho’s district out of the San Ramon Valley and both she and her East County colleague, Fredrick Glover, are running unopposed. Piepho faced a heated challenge from former Dublin Mayor and state Assemblyman Guy Houston four years ago, but got a free pass this time around.
San Ramon Valley voters will see plenty of campaigning for its representative on the board as Danville Mayor Candace Anderson faces off with Tomi Van de Brooke, former chief of staff for Piepho and current community college trustee. Long-time Supervisor Gayle Ulikema retired, leaving the vacant seat.
Serving as a supervisor is a pretty thankless, although powerful job. Many key decisions get made on the boards, but their ability to raise revenues is severely limited.
The counties provide the safety net and are subject to way too many unfunded mandates from the state along with inadequate funding passed down. That said, as political jobs go—there are no terms limits, benefits are good, and the pay—with Alameda County’s matched to Superior Court judges—is reasonable.
And the power comes in with positions on critical regional governing bodies such as the oppressive air board and the Metropolitan Transportation Commission, which doles out transportation dollars in the nine Bay Area counties.
Turning to the partisan races, the redistricting, although done by a citizens’ commission, resulted in districts that are so one-sided that two East Bay incumbent senators drew no opposition and the incumbents are uncontested in three Assembly races.
For the Livermore Valley, the redistricting eliminated the pizza-cutter approach that diced up the valley previously—now it’s one Congressional district (incumbent Pete Stark facing off against his younger challenger Dublin Councilman Eric Swalwell along with independent Christopher Pareja) and one state senate and assembly district.
Incumbent state Senator Mark DeSaulnier and Assemblywoman Joan Buchanan both face Republican challengers although the registration favors the Democrats enough that it’s unlikely to draw a great deal of party money.