I personally think Season 2 has taken too long. I suspect that FD agrees with this observation. What they will be able to improve in future remains to be seen. Meanwhile ED still remains one of most complex games I have knowledge of to date, and struggles of competition to produce anything similar indicates it is just beyond colossal task than even most knowledgeable supports have imagined.
Still, I want to point out that Season 2 got lot of infrastructure development - persistent POIs which can be introduced to game without client update? NPC avatars? Work towards more fleshed out universe? YES YES YES - which I suspect wasn't planned before initial outing of Season 2. THIS is way more important, and gives me hope for post 2.4 updates which definitely will build upon work done for Horizons in this regard.
Will complaining cease? Of course not. But that's doesn't matter that much at this point.
As for Season 1 features - I think biggest disappointment is that they haven't been fleshed out. CQC needs bots play to make it a thing, other than that it was awesome addition. Also CQC would benefit heavily from cross play even just between XBO and Windows. And then there's PowerPlay...to be fair, initial trashing of this mode has doomed it at this point. Majority of players claim it as grind - besides giving huge amount of credits - just to get stuff. Metaplay is done by small percentage of players. So it is a bit stuck in chicken and egg situation. Sandro pitched PP for 2.4 post upgrades again in latest stream and it is very visible he has huge plans for it. Just numbers doesn't support it. New comers and casuals are not interested in PP because it has negative meta game connonations and power players are way to cynical to care.