A huge example/problem is the recent case against Girls Do Porn, where it turned out a huge number of performers had been lied to about whether or not their videos would go on the Internet, pressured into staying through shoots that fell outside the bounds of what they'd been agreed to, and in at least a few instances, raped.
It's likely a big part of the interest in requiring education/licensing prior to entering the business would be to make sure everyone knows the rules and what they can do about companies falling outside it. Sites based on getting first-time performers would have a much harder time sticking around without proving they were meeting all expectations.
So it's probably less about keeping women out of the industry than ensuring they're not taken advantage of. It's the same reason legalizing and then regulating prostitution would be safer for prostitutes than what we have now. Adult filmmaking isn't illegal (solely because of first amendment decisions), but it's also pretty poorly regulated.
(This comment is meant to add context, it's not support of the bill. There's huge privacy concerns, because government databases tend to not be super private, and a lot of families pretty much disown adult performers if they find out. But I wouldn't assume this bill has malicious intent, there's good reasons to add regulation too.)
Twenty to eighteen year olds are the ones being kept out under the bill - which seems dubious even with all of the other "legally an adult but discriminatory law" standards already in place.
