I disagree, they concluded that the public didn't like paying upfront for a "Season" of promised updates due to the poor (v expectation) sales of the DLC and saw an issue with Horizons going way over its original intended time span by a year and the community perception of half-baked content, a combination of both would have been a big disruption to the original funding model. It was stated as such by the time it was finishing around 2017. Beyond Season was basically a gift to the community and was striclty limited to one year, at the time it was painted as a sort of apology for the protracted completion and the resulting loose ends created by the long list of Horizons promises by refreshing some of the untouched core gameplay loops. But I would imagine it was also about re-enforcing the core product for the impending long development gap of the New Era.
Fundamentally, the fact is that FDev turned Horizons into a bit of a dog's dinner and then said "We don't like the idea of doing
that again".
Honestly, I'd be interested to hear from anybody who thought Horizons
didn't provide good value for money overall.
Let's face it, Horizons kept ED in development for more than half a decade... all for 20 quid!
The problem is, if FDev's production team was on their toes, Horizons
should have lasted 12-18 months, should have been feature-complete and bug-free by that time and they should have had another expansion (either season or standalone) ready to ship at the end of that time.
However, none of that stuff occurred
and FDev had LEPers to answer to, so they kept plodding away at Horizons, used Beyond to revise some stuff that needed doing to the core gameplay (the navigation updates) and then threw in Nu-mining to give Beyond some real value (and, fair play to them, nu-mining WAS an impressive addition that they didn't really
need to add to a free product).
In that context, it's obvious that FDev would feel like they don't want to do a "season" again but the point is that it's their own fault.
If they'd got Horizons "finished" in a realistic time-frame
and had a follow-up ready to ship, they wouldn't have had to keep on supporting Horizons for so long.