TV shows don't reflect real life and aren't meant to. They're written by people and are there to tell a story. In most cases, they're written by people that have blind spots for women.
Even if the Valley is steeped in sexism, I think it's perfectly fair to ask that our (constructed, scripted, designed) entertainment rises above. Most movies and tv shows pander overtly or subtly to white men. We techies are supposed to value performance and merit over superficial details like which bits dangle or bounce so I'd like to think that a show about the tech world could do better. Especially after the would-be Maker show was ended by a techie response to overt sexism.
But frankly, we don't even have to do better than real life. There are female techies, even in the Valley. Mike Judge just needed to include a couple to tell their stories as well. It sounds like this show isn't even measuring up to the already very sexist culture of the Valley which is saying something.
Maybe some people find that entertaining. I don't. And I don't see why anyone should have to step into an even more sexist (and racist?) world to get some light entertainment. "Lighten up" sounds like a really dumb suggestion.