The game has only been in proper development for around 5 years, it takes at least 7 years for a project like this to be even close to being ready. You cant really count development when it was only a concept and a basic demo back at the end of 2012, it also takes a while to set up a network of studios to even start developing a game. In reality since most of the staffing of the studios that would be 4-4.5 years in actual development, with a year of very little actual development as a concept, which in reality a normal studio would go straight into development.
With Chris Roberts it may take longer than normal to get the game ready but without him we wouldn't even be getting a game like this that many people are wanting.
At the end of the day its Chris Roberts game to finish the way he wants it done, i would rather wait for it to be ready and with all the features needed, instead of bolting things on afterwards.
I have played all the games similar in the genre and they don't have that space game spark, i only play the alpha now and then on new patches as not to spoil the game for release, the gameplay in SC feels more involved than all the other games out there and most of the core mechanics are not even in the game yet.
Why don't we wait for full 3.0 release and that will start to show what the game will start evolving into, yes it may not run smooth all the time but performance issues can be fleshed out in a more complete state.