The Home Country rule is that a TV station that is licensed to a city (San Jose) should be required for cable systems to carry the affiliate in their home county where the TV station is located (Santa Clara County) but other markets opt to omit from their lineup, and while KNTV's news content consists of Santa Clara County, they sparingly went to Salinas/Monterey, even though they do not mention that they cover that area.
In the 1980's, most cable systems in the Bay Area (except for Santa Clara County) dropped KNTV. The station used the home county rule to remain on the Santa Clara County cable systems. In fact, at one time KNTV was owned by Gill Cable in San Jose.
It was a rare exception to have a station licensed in one DMA, but for network rights was serving another.
Funny thing about that is on air, they were the "South Bay's News Leader" and "The San Jose News Channel" with little or no mention of the Monterey Bay area. They were in fact on cable in Monterey, Santa Cruz and San Benito counties and receivable on the air.
KNTV apparently wasn't doing the greatest in the 1980s. First, it lost network exclusivity in the Salinas-Monterey market, then it was removed from most of the cable systems in the Bay Area. So KNTV was missing completely from many Bay Area televisions, and it was competing with KGO without the benefit of network exclusivity in Salinas-Monterey on those cable systems that carried KGO.
KGO, KPIX, and KRON were carried on many but not all cable systems in the Salinas-Monterey market until the mid-1990s. At that time, because of retransmission consent laws, the Salinas-Monterey stations got KGO, KPIX, and KRON removed from the main cable systems in Salinas and Monterey. The Salinas-Monterey stations felt that the San Francisco stations were cutting into their local news viewership. KTVU was not removed because it is "significantly viewed" in Salinas-Monterey, and KQED was also not removed.
KNTV is likely doing much better now as the Bay Area's NBC affiliate. However, San Jose was not a good location for an ABC station with another ABC station located just a few miles north, in San Francisco.
Another interesting fact is that KSBW in Salinas in the early 1980s moved its transmitter from Fremont Peak in Salinas north to the Santa Cruz mountains. This allowed KSBW to directly compete in the Bay Area market OTA, and there were places in the Bay Area where, due to terrain, KSBW actually was more receivable than KRON. I am not sure if KSBW was ever picked up by any Bay Area cable systems.
Shortly following KNTV's transition to NBC, KSBW moved its transmitter back to Fremont Peak.