Sorry that my response isnt the most thought out, theres definitely better ones in this thread, but i just wanted to get my feelings about this out.
I just think that Solo/Private play is JUST as important as Free play with randoms.
As an example, i used to play tons of Warframe back then. I had some amazing Public experiences, sometimes just sitting with randoms in a survival mission for an hour straight just having a GREAT time (and i hope i will have times like that in the hunting grounds aswell).
But there were just as many times where i wanted to play solo or with a friend or two for various reasons that honestly dont matter, the thing is that i WANTED to do them alone/with friends.
I will use public hunt in the hunting grounds a lot, yes, but i also KNOW that i will want to be alone or with a friend there, without some random person running in and ruining my/ our experience.
That all makes sense to me! Sometimes you want to just play with friends.
We want to know how people feel with this specific feature before adding private matches, because it could very well be that another feature is instead better for "just with friends". It's all a balance and we are definitely not saying no to solo q / private matches - we are saying we won't have it on launch and then will reassess to see what's best for the game and the players