Big money? Bwa-hah-hah. The suppressor industry – with perhaps the exceptions of Remington Outdoors and SigSauer – is made up of a number of small businesses. Some are mom and pop operations while others may have 2-300 employees.
Silencers are a safety item. They do not totally cut out the sound; they merely muffle it to a safer decibel level. Anyone who says differently is just restating myth and legend.
I just had my annual hearing checkup on Monday. I shot some in my younger days without hearing protection, attended some auto and boat races with no hearing protection, and, of course, a few rock concerts. I now suffer constant tinnitis (ringing in the ears) and some hearing loss.
About the only “big money” who would benefit from keeping suppressors banned are the hearing aid manufacturers and I doubt even they would want to build business that way.