This desire to separate 'good porn' from 'bad porn' is intellectually dishonest.
As TheBrandyButterflyEffect says, feature porn is gateway porn, it is used to groom. So when Mr and Mrs Average indulge in a little naughty but lite porn watching to spice up their sex lives, they are creating demand.
Demand is created for girls and women who will consent to being filmed having sex in exchange for money. Women who need money, and who have been sold the glamour empowering myth, see this sort of feature porn as being an option for them. They won't do any of the hardcore stuff.
So they get an agent (it is almost impossible to work in porn without one) and they fill out a form with a list of acts they are willing to do. Those acts all have a price tag - vanilla girl on girl sex pays less then group sex with several men. Anal sex pays more than oral. Double penetration and especially double anal carry even higher price tags. And the agent gets a percentage of the women's earnings. If she doesn't work he doesn't earn. If she sucks some cock he earns a bit, if she gets face fucked and does some double anal he earns rather more.
So she shows up on set ready to do a scene and then the producer announces that they are going to do one of the acts that isn't on her list. She either does it or doesn't get paid. If she doesn't get paid neither does the agent, she will find it difficult to get work, she will have a reputation for being unreliable and unprofessional. And she's probably about 18 or 19 years old, the only woman in the room, she's probably naked and she's being coerced by a group of older men who do this sort of manipulation for a living. So she does a shot or takes a toke or a snort and does the scene. A few months later she's doing ATM and DPs, she got STDs and substance abuse issues.
This story is told time and time and time again by people like Shelley Lubben and other women who have exited porn.
They talk about dissociating as a technique to get through scenes, they talk about how once your boundaries have been broken you start to feel that you 'might as well' do stuff you said you wouldn't before - you're a whore already right?
There is no 'good porn' and 'bad porn' - there is no vacuum. There is just porn, the multi million dollar industry which needs a steady supply of young fresh woman. Mr and Mrs Average are just as much part of the process as anyone else who is involved.
And for those who think that hardcore porn is not popular - just visit one of the websites at the top of the results and check out the number of views for vidoes such as the ones I listed above - there are hundreds of thousands of views for the videos, and there are countless videos - somebody must be wanking to this stuff.