No one has paid a dime for content since they purchased Horizons - for some, that was in late 2015.
In other words, they have gotten accustomed to not paying for content, and enough time has passed that some of them might complain about it.
There are others who will complain that they didn't get their money's worth out of Horizons/Beyond, and shouldn't have to pay for whatever in the future.
Did I really need to explain that?
Edit - Commander Whitman was kind enough to point out the date error in this post, which has been corrected. Almost 3 years of not paying for content, instead of the almost 4 years originally implied. Thank you Commander Whitman, I do hate to say things that are factually incorrect.
Riôt
You did need to explain it, thanks. Couldn't figure out where you were coming from. It's a good point.