public broadcasting is a counterweight to commercial media - but will it survive?

Growing up I always thought of channel 21 WXXI (Rochester, NY) as "the boring channel". It rarely had any "cool" shows on. Perhaps the occasion NOVA program would catch my eye, or when I was even younger, the afternoon cartoons were there when the networks were broadcasting their overly dramatic soap operas. I also occasionally enjoyed an episode of 'Antiques Roadshow', thinking maybe there was something in our basement that would thrill the appraisers.
Yes, I suppose I did not grow up a normal child, with only five television channels to choose from. Looking back, I relied on public broadcasting during the networks commercial breaks, or when absolutely nothing good was on. I didn't have Nickelodeon or MTV. Instead I would find myself learning how to make a good lasagna with Lidia or how to install a new window on 'This Old House'.
Back then I never realized the value that public broadcasting had for television. I didn't know about the corporate censorship that had a hold on the networks programming or that there was more concern for making money than showing a solid program. Public broadcasting provides the type of alternative media outlet that is supported by its audience, therefore is producing for its audience. A symbiotic relationship.
Yet with the popularity of cable television, and now the internet, I'm not sure how much longer public television can survive in the United States. Always known for not having commercials, there are now underwriting spots grouped together after each program for some advertising revenue, but it may not be enough. Most of my generation and those after grew up with over 500 channels, public broadcasting wasn't even on their radar. Will it be lost as the generational pull continues?