Because he promised much more than they could deliver at launch, and when you screw up a launch, it's very hard to turn that negative perception around.
They've gone well beyond anything they promised. Nearly everything that's been added in all 4 updates is something that was never promised. This is like complaining NMS isn't as small as was promised. If you want it to be closer to it's promised state, reinstall it without updating it.
I'm just explaining why people still feel this way about it. See post right above yours for reference. I know the game is much better now, and I was never the one complaining in the first place, I'm just saying it's hard to change people's minds on something they already have a negative view of.