Well, I guess I'm number three. I find it's more convenient than dragging lots of apps to the Dock, putting aliases on the desktop or wandering through the Applications folder. I launch most stuff via Launchpad, reserving the Dock only for apps that I often want to use as a drop-target (e.g. Emacs) or those that display badges I want to see (e.g. App Store or Messages)Since Apple introduced LaunchPad, I have encountered exactly two people who use it.
I do take the time to organize my Launchpad, much like I do on my phone - putting everything on one screen, grouped into folders. On my laptop, I used the four-finger-pinch gesture to bring it up. On my desktop, I've remapped the F15 key to bring it up, which I never type by mistake. (I have my keyboards configured so the F-keys generate F-events, so I have to type Fn-F4 to bring up Launchpad with Apple's default keystroke)