The reverse engineering (when involved) should occur under the relevant laws, to avoid any ambiguity and "religious" understanding of the reverse engineering approaches: some community members of other projects tend to abuse the "ideological superiority" of the chosen project, by bending, obscuring and twisting the processes.
Examples are notable comments by project leaders like Alexandre Julliard citation "You should not look at ReactOS code at all, a lot of it is reverse-engineered using methods that are not appropriate for Wine. It's not a usable source of information for us." - source https://bugs.winehq.org/show_bug.cgi?id=50464#c6
Such comments, historically, speaking from the shared experience of multiple contributors, tend to create a harsh "us vs them" environment for everyone, implying that the "other" project is somehow "bad by default" because it "does not follow" some obscure, unclear, never fully specified rules (even when it's completely unintentional and the rule authors acted in good faith).
For example this article never really addresses "why?" question: simply stating the set of arbitrary rules in practice worked as a doctrine to enable people to discard any competitive project as invalid, and virtue signal Wine's "ideological superiority and coding practices purity" and do wild assumptions about every contributor strictly following the doctrine, while in practice they may not (yet still operate under the correct laws).
While it may look like Wine project follows some "clearly superior" rules, ReactOS Project actually follows nearly identical rules as seen in the relevant ReactOS FAQ wiki page citation "ReactOS consists only of clean-room engineered source code". Alexandre Julliard’s contradictory claim creates an absurd situation where differing interpretations of clean-room practices foster unnecessary division in the FOSS Win32 ecosystem. Note that the problematic claim is referenced by the Wine wiki page below as a way to ensure the truth by the reader in the article, making an impression of some verified fact, while in practice it simply links to a single two-sentence ultimate claim by Julliard, which leads the reader to psychologically assume that ReactOS developers are bad actors, driven by the impression that Wine approaches somehow are more faithful to the law (which in practice is not guaranteed per se, as any contributor should actually follow the word of law, not some arbitrary rules or single-country precedents).
This article is not intended to raise tension between the projects. Quite opposite: being more open about the actual issues - i.e. legal uncertainty of reverse engineering practices - lowers the amount of confusion in the communities. Some occasional damage towards individuals and projects has been seen in the past, thus Greentea OS embraces the opportunity to acknowledge those problems and make all of FOSS Win32 ecosystem more welcoming to the future contributors.