The ability for any one entity to disrupt everyone's ability to listen and transmit equated to extreme tyranny by the minority. Therefore, broadcasting requires a governmental body to assign and protect airwave rights in order for the airwaves to be useful for broadcast. The failure of the market to self-govern broadcast allocation is an example where market failure occurs and an institution must govern over all broadcasts for the market to exist. The answer to both is yes. There is market failure that justifies future investment in public broadcast television.
Insufficient incentives exist in TV broadcasting to benefit society.
Even more surprising, government sponsorship should increase since the failure of the marketplace is likely to accelerate. Simple, some individuals are not represented by commercial broadcast television. Advertisers do not market to these people. Consequently, television channels do not attempt to attract or program for this class. Even worse, this class of people is likely to become more alienated with society as programming is sent through cable systems.