This is rather simple.
People DID their research. Some thought they were buying a MULTIPLAYER game you can PLAY WITH FRIENDS.
And all they got is a single player game, with multiplayer and co-op parts bugged / non functional / non existent.
I have seen Youtube's of people jumping together, around 6 people, and yes I am sure it took some work but it is doable working together, OK comms can still be a bit hit & miss, using TS is not ideal but some make it work. While I don't mind waiting, I do understand your POV on this.
I admit wings not being in at launch was a disappointment to me too, but it is something that we know is on the way "soon"(TM).
Someone posted earlier that FD dropped solo offline (a major change) so there is no reason to think FD won't change the game on recent suggestions to segregate the matching & saves, ok solo offline got dropped, they said they couldn't make it work as they wanted to, etc, etc (this has
saved them time & money by dropping it, I am not saying I agree with but it is
less work / money for them), when they were working their butts off on launch (time being very limited), and yes one day I would like a solo off line copy if it was ever possible.
I am sure they are now equally busy on "wings" amongst other things, we know they are grafters from previous patches etc, sometimes almost one a day for a week, changing the game to split matchmaking now would
cost more in time & money and delay the launch of wings and other features, Michael Brooks posted that mining was the bare minimum they would release, this too still needs love, DDF I believe mentioned drones to collect the fragments etc.
So when would FD (theoretically) do this extra work, before wings, before mining, before system rep improvements, system map issues / trade routes, more BB missions & making them more interesting, (murder penalty's (not pirating, PKing) that might actually get more traders in open!), fixing netcode that might prevent people seeing each other in open, making anarchy's more dangerous than policed systems (you get where I am going, all the stuff that needs to be done for the benefit of all of us, not just a few)
It's too late for the "I don't wan't people to bring big ships from solo to open" crowd, that boat has sailed already, unless we all get wiped again, (has anyone seen CMDR Thrust from Bradford recently?, he might know, I think he is a FD mole, but don't tell anyone, Sshhh

)). You will never know that the player with every ship in the game & 1,000,000,000,000,000 CR earned it in solo or not, BTW I played since PB, I didn't wipe as I never exploited a bug, still never even seen a rare, and I own a type 6 & a Cobra both close to A rated, ~ 3 million CR & I am now working towards a viper, lol you don't need to worry about me giving you too much trouble, I would rather give some cargo

.
I will never work 3 separate accounts, I don't have the time, if I was locked into one I would chose private groups, which would be a shame (and not the game I bought and paid for including the DLC up front), I generally play a little in the "mobius"group, in solo if I am short on time (most week nights, if I do get an hour or so), and open on the weekends when I have a bit more time and might be feeling a little more sociable.
I took my type 6 out last week in open with the intention of getting pirated for the first time, I got lucky I got robbed by a gentleman pirate it was great fun, why should I not be able to do that again if I like to play in solo too sometimes?