I think @skeletonjelly's point is that the reverse engineering of ObjC reveals much of the original unobfuscated source coude, thus giving away proprietary data?
Correct. ObjC sits somewhere between C and Java in ease of decompilation. Logic and arithmetic code is compiled just like C but all of the object-oriented options are readily exposed. Message passing is used, letting you hook into every part of the program and find the original class, method, and field names and all operations on them. ObjC is very dynamic and introspective which makes reversing it much easier.