You could say no one is going to want to watch YouTube videos with annoying ads that you can't turn off, or no one is going to want to play an app with annoying ads you can't turn off, but millions of people do this every day. They accept this price for their free content. The ad-supported digital comics would not be presented in a browser or something that makes it easy to circumvent the ads, but as software with Digital Rights Management protection. Would some people crack it? Sure. Everything will be cracked or pirated no matter how freely it is given. But your average user would accept the free comics as presented.
I couldn't guarantee comics would find a wider audience, but here are the barriers as I see it:
1. Price, especially price per minute of entertainment, which is among the lowest of any medium.
2. Availability of the physical product. Comics, especially periodical comics, require a special trip to a bookstore, often a specialist bookstore.
3. The problem with digital comics is that they are hamstrung by the need not to compete with the print product, mainly manifested by selling at the exact same price. So go back to number one.
Free ad-supported digital comics break down all three barriers. And by distributing them through social, app, and viral channels, you get your product in front of many more people who might be interested in trying it.