Comment by bombcar
If you have multiple ways to do something on a computer/phone, some relatively large percentage of people will fumble around until they figure out a way to do it - and then do it that way forever.
So if someone accidentally triggered Launchpad and realized they could see their apps, they might use that forever (not knowing you can put your Applications folder in your Dock and use it as a start menu lol).
they've had a launch-pad-ey thing forever, I remember when our school lab had Mac IIs and Performas, and there was some simplified UI on top of finder which basically was all your apps in giant rectangular icons. I forget what it was called though.