Sadly, I can confirm this is true.
Most single-seat customers are fine, of course, but a very vocal minority can cause a lot of problems.
I believe it's due to the mindset shift. If a team or company decides to use a specific software, people are more likely to accept the decision and learn to work within the tool's features and limitations. The cost of switching tools is high, so they tend to stick around for a long time.
Single-user freelancers can change tools at any time, because they don't have to negotiate with anyone else. As such, they feel they have more leverage in threatening to cancel their subscription if the company doesn't cave to their demands.
Most of them don't realize that the company isn't making much, or any, money off of their single-seat license when they're consuming hours of customer support or social media engagement time every month. It's better to see the squeaky wheels just leave the platform.
For another data point: At scale, you get a lot of threats from people claiming they're going to Tweet about how bad your product is to their thousands of followers, or write a newsletter about how much they hate your product, unless you implement the specific feature they're demanding. These threats exclusively come from the single-seat users, because no company is dumb enough to try to extort another company with threats of tarnishing their reputation in public.
It's unfortunate, but it's true. It's vastly easier to just deal with enterprise customers or larger teams who have better things to do than tie up customer support time for every little complaint or suggestion (or demand)
