I think you substantially overestimate the number of providers that behave ethically with regards to DNS and substantially underestimate how many people have shitty ISPs. You seem to have a very skewed view of how the number of internet users distributes across the world. Even in Europe, providers are not refraining from hijacking DNS and using DNS blocks for certain sites.
I think you substantially underestimate the number of networks that use split-horizon DNS for their functioning, and where hijacking the DNS is going to cause significant breakage.
No, but they do exist and specifically in this case (since they mention public wifi) pro users capable of configuring their system dns might not be the only target audience