Some content is just bad; but it doesn't have to be

There are a few segments in the marketing industry that seem to acquire senders with bad mailing practices. Nutraceuticals, male performance enhancing drugs, short term or payday loans and gambling have a lot of senders that treat permission as optional. The content and the industry themselves have garnered a bad reputation.
This makes these industries extremely difficult for mailers who actually have permission to send that content to their recipients. Working with this kind of sender, sometimes it seems impossible to get mail delivered to the inbox, no matter what the level of permission. Even when it’s double confirmed opt-in with a cherry on top, all the care in the world with permission isn’t enough to get inbox delivery.
This doesn’t have to be the case. Look at the porn industry. Early on in the email marketing arena there was a lot of unsolicited image porn. A Lot. So much that complaints by recipients drove many ISPs to disable image loading by default. The legitimate porn companies, though, decided unsolicited image porn was bad for the industry as a whole. Porn marketers and mailers adopted fairly strong permission and email address verification standards.
It was important for the porn marketers that they be able to prove that the person they were mailing actually requested the email. The porn marketers took permission seriously and very few companies actually send photographic porn spam these days. Even the “Russian girls” spam doesn’t have not safe for work images any longer.
Because of their focus on permission, in some cases revolving around age of consent in various jurisdictions, the porn industry as a whole is not looked at as “a bunch of spammers.” Porn content isn’t treated as harshly as “your[sic] pre-approved for a wire transfer” or “best quality drugs shipped overnight.”
Just having offensive content isn’t going to get you blocked. But having content that is shared by many other companies who don’t care about permission, will cause delivery headache after delivery headache. This is true even when you are the One Clean Sender in the bunch.