@cloudlink My feelings exactly!
When I found RetroPie I loved that it was something that you needed to tinker with to perfect. I'm still not convinced I've managed to perfect everything on mine yet because I've barely touched MAME Emulation on my NES build yet!
It took me back to when I was in college messing with Photoshop to make wallpapers for my PC desktop because the ones I found online were not what I wanted. I found these the other day on my current PC (I loathe to delete my old data and it follows me around) and I've made about 200 of them! Like I ever changed my wallpaper that much!
As you say though, if people want something slicker and easier to use then there's other Emulation options such as the Nes mini or iPhone/Android emulators. I've got a really powerful emulator personally; it's called my PC.
I love RetroPie because it makes this little £35 circuit board thing with flashy lights and bare input pins sticking out into something wonderful. Plus, you can shoehorn it into things and make amazing things happen like building your own Arcade Machine! Things that dreams are made of people. Dreams...