To be fair, these complaints -- those you bulleted -- validate the poor star-rating. I can't imagine a majority (Re: 2.5+ stars) being given to an application that more-or-less tucks away all of these smartphone features.
That describes like 1,000+ apps with the word "launcher" in their title, and yet a lot of them are 4+ stars https://play.google.com/store/search?q=launcher&c=apps
The 4+ star rated launchers add functionality to android.
Oh well, they thought they could simply "take over" the entire, front-facing experience of the phone. They probably would have had better success trying their hand at releasing a better widget, surfacing the same experience without removing the notifications bar, apps tray, etc. Being resizable and able to coexist with other widgets (eg. 1x4 Search, 4x4 FB, 1x4 App tray) would appear to be a lot more welcoming.
For example, I use Nova Launcher, and when you first install it, it's entirely identical to the default launcher. Most people using my phone don't even know that it's not the default.