I had read about Frank dumping the original group and his opinions about their technical shortcomings. So I was surprised when I saw Zappa live in November, 1975, and Roy Estrada was back in the band on bass. This was much more of a jazz/rock fusion group, with an emphasis on extended improvised solos. The band members were Andre Lewis, Norma Jean Bell, Napolean Murphy Brock and Terry Bozzio, in addition to Estrada and Zappa.
During that concert, Estrada fit in well and did not seem to struggle at all with the fusion music. Zappa scornfully introduced a solo by drummer Bozzio with "here is your new hero, your new Alphonse Mouzon on drums!" Zappa introduced his own extended solo by saying, "and here is your hero, John McLaughlin, on guitar!" again, in a scornful voice. There was quite a negative vibe from the stage--several people commented on it to me after the show. The vocals were weak and Zappa did not seem happy at all onstage.
So by 1975, Frank seemed to be tired of the jazz rock fusion scene, and to not value instrumental chops much. In 1969, he spoke negatively of his sidemen who did not have chops. Who could win with him?