I don't understand what you mean. Why is drawing attention is bad in this case?

The vast majority of ROMs are not licensed from the original authors, and are used in violation of copyright. Many people use emulators to run games they don't own; that holds even more true for arcade cabinet ROMs than for home game consoles. And most emulator authors have a passion for the games and systems, and don't actually want to see harm done to those companies; they often build emulators out of the desire to see games and systems preserved and made available to a new generation.

On top of that, many arcade machines already had commercial cloning going on; unlicensed or modded arcade machines with clones of the hardware and copies of the hardware were common.

So, developers didn't want to do anything that would come across as encouraging commercial use of unlicensed game ROMs.