>a rogue ad-blocker app is exactly as dangerous as a rogue VPN service. Fortunately, because these ad-blocking apps are usually open-source, there are limited opportunities for bad actors.
I find it naive to state this when earlier he noted that he's suspicious of free services without a clear funding model.
Sure, open source is certainly better than closed source, but its not like somehow magically it prevents exploitation. There's plenty of examples especially in a small project like this with few eyeballs. So why question the funding model of a free VPN but not question the funding model of an open source project? We just assume its being done out of good will? I find that perspective naive.
Not that this entirely clears the skepticism, but to directly address the question as asked: blocking ads scratches a clear itch for the author. FOSS works great because software has no marginal cost, so as long as someone wants it to exist badly enough to make it so, there's then no reason not to give it away to anyone else who wants it. Providing a free VPN service to the world is quite a bit less likely to be an author-itch, and actually incurs a cost.