I think perhaps you are confusing morals with ethics. Morals are a subjective matter, unique to each person, and are derived from their own individual values.
Ethics were designed as a more objective framework that can be consistently applied in a society so that groups may be able to reach consensus about decisions that affect others. I have yet to see any argument that developing and publishing software that allows people to download public information from the web is unethical, especially considering the fact that you cannot download any information from a webserver that that server does not willingly provide to you. You send a request, and perhaps you receive a response—or not. It is wholly within the determination of the server what, if anything, it sends to you. My software speaks plain ol HTTP, no hax or subterfuge or fuckery of any kind.
Indeed, such HTTP client software development and distribution is widespread in our society: you're probably using some software like it right now to read these words. Other tools that perform this function are shipped with every single install of most OSes. It's some of the most common software on the planet. When you browse Mastodon or Pleroma instances, software on your computer is doing the same thing that my software would do, if you ran it.
Despite the fact that some people are irrationally upset over people's choice of HTTP clients with no justification offered, the burden of proof remains on you or anyone else who has a problem with my software to explain why, from an ethical perspective, I shouldn't be writing it or publishing it. No one has offered such an explanation to me, nor can I, in what I think to be a thorough consideration of all the possible consequences or systems of ethics which might apply, discover one myself. I do not believe that such exists, considering the circumstances of how common even advanced HTTP client software is. If you have one, please speak up.
Remember: whether something is moral or not is a personal opinion; it cannot be right or wrong. Whether or something is ethical or not, however, is more or less an objective analysis within a given ethical framework. It is not an opinion.
I mean, it is legal. Stopping him wouldn't work well.
Sleazy? Arguably. Allowed? I mean, it's not like it's pulling any magic tricks. It's operating within what the protocol (and the law) permits. People could use a better protocol that doesn't have these problems, but hey, who cares, right?
Even though several people are saying that what you're doing is unethical, you're effectively saying:
> "Screw you, I think it's OK, so I'm going to go ahead and do it, and no one can stop me."