Because that's not what happens with stolen catalytic converters, so it wouldn't change anything. Stolen cathalytic converters are valuable due to precious metals that can be extracted from them.
On the ground, the situation with CFC refrigerants is probably a lot leakier (pun intended) than you think.
There are a lot of AC systems repaired at stations that don't even own a recovery machine. (This is legal, so long as the system has already leaked out to nothing before starting the repair. I suspect that gets a wink and a nod a fair amount of the time.)
Some refrigerants can only be legally sold to resellers or to users with an EPA certification. Sounds strict, huh? Well...the 609 certification test can be done online, is open book, and cost me $25 and 15 minutes to get.
Probably has to do with not being able to earn a few hundred dollars in a few minutes with the education of how to use a simple cutting tool from Home Depot.
