First of all you need to separate the OS from the apps, would you say that Windows is a inferior product because it has Internet Explorer as a stock app? As long as Microsoft lets me install Google Chrome as my default browser I don't really mind that stock browser. And this is what people like with android, the freedom to choose. Perhaps you are from the other group of people who like everything to be decided for them, just give me a phone that I don't need to do anything to make it better, and there's nothing wrong with that, and for this group the iPhone is the perfect phone.
Now about the lock screen, What's app doesn't have a widget to display new messages, but you can use the pop up feature found in the whatsapp settings, and make sure to enable the pop up when the phone is locket. (I think you can choose if it pops up even when the screen is off or not).
But with emails, or any other app that gives you a widget, you can enable lock screen widgets under settings/security, and then from the lock screen you long press on any plus symbol to add your widget.
