You can disable specific warnings as a project setting, not just with rustc/cargo but with every build toolchain I've used in the last ~10 years. It's very common for me to find a project with at least one specific warning disabled. That really isn't a "trust me bro" -- people can look at the project, see which warnings are disabled, and decide for themselves if that is reasonable.

The remark about style warnings is really alien to me. Style warnings are something I'm accustomed to when programming in nearly any language. I can't remember the last time I used a language where whatever IDE I happened to be using didn't have style warnings. And I've never had trouble adapting. "Oh right, C# convention is PascalCase methods. Oh, Java is camelCase". In fact I've been jumping between a C# project and a Java project recently, and I haven't been finding it difficult. Rustc having some linter-type warnings built in is a bit novel I guess, but really not a fundamentally different experience. It's really not any more difficult to disable those warnings for a Rust project than for a C# project. I don't think I can understand calling that "not okay".