Quote from ironwheal
Frankly speaking, reverse engineering is not stealing and is perfectly legal in a lot of jurisdictions. But yes, i concur, it's better to stay out of it and instead put the work into making replacement mods better.
Decompiling code is nowhere near the concept of reverse engineering. Decompiling proprietary code and offering it up for public download *is* stealing/copyright infringement. Worse, it's distribution.
Further, the global internet is not governed by what "might" be legal in some arbitrary jurisdiction.