It happens all the time in the banking arena. Banks are frequently used to deny market access to businesses that are undesirable to the federal government but are otherwise legal businesses.
This is actually a great analogy. Its all about reducing risk for the overall business.
I hadn't thought about it this way. I assume marijuana dispensaries/businesses are one of the examples you're referencing?
Porn type content also tends to have trouble with many services like payment processors. A simple example is paypal doesn't support most porn related content. I also recall a video game company that makes weirder porn (stuff like hypnosis hentai) saying hypnosis is a trigger for some payment processors so they've had to avoid that terminology.
And why sketchier businesses, such as casinos, had to turn to organized crime for loans and funding.