Not being in the US it's hard to say really, but it seems that cable shows can take more risk, so you end up with better shows in general.
Being at a far remove, the examples in the original post (and many more could be added,) do show that with one significant exception, the programming in cable, premium and basic, is at the least no more innovative than network television. (Actually, cable may be less innovative.) And, if taking risk by presenting something different is meant, there is also no real reason to think that being risky will mean a smaller audience. That appears to be snobbery instead, as in "The filthy masses don't like good stuff."
For example, consider the original Law & Order. For decades television was wedded to the one hour cop show and the one hour lawyer show. Law & Order is a half hour cop show followed by a half hour lawyer show. If that wasn't innovative, nothing is. That was a risky venture, but it was instantly popular. (None of the spinoffs copied the format.)
Also, for decades, television shows had a flexible approach to time, with the time between scenes varying according to narrative need, understood by the audience according to context and convention. Then, 24 presented its story in real time. That was innovative, and risky, but instantly popular. Pushing Daisies was extremely innovative but was instantly popular.
Cable is actually less likely to take liberal (forget leftist) viewpoints on political issues. In the few instances of cable programming even being aware of political issues, they are conservative to far right. The Wire was a partial exception, except a glaring tendency to make the heroes more macho, even the gay one! But The Wire had troubles surviving even on premium cable. Politically speaking, cable plays it safe.
The freer attitudes to vulgar language and sexuality on cable are not especially risky, since they are more in line with the actual practices of large numbers of the population. They are influenced more by real people. (In that sense, attributing the "quality" to the financial model is correct, in my opinion.) But the networks are influenced more by corporations, which brings a strong reactionary influence. The amazing thing is that it still was on network shows like ER and Brothers & Sisters that once would see a country at war in Iraq, for just one instance. I suspect that the social position of Hollywood producers, directors, writers, etc. comes out more in the cable productions. (Again, The Wire is a partial exception.)