The other security issue mentioned, piping curl into sh isn't really that big a deal. As long as you're a) using HTTPS and b) you resonably trust the source you were probably never going to read the script anyways.
I mean, when I first evaluated this app, it didn't even have a sane launcher script. Instead, ~15 lines of ruby config and a ruby script that I had to follow just to discover it was a weird, idiosyncratic way of executing "docker run".
Edit: I am not saying that Docker is somehow inherently flawed in this respect. It's solved a lot of problems for me and you can build great, well-architected stuff with it. But there is a trend to use it to wallpaper over poor development and deployment practices.
Now the nice thing about docker is you could have spent about 5 minutes to trivially docker run the app, decide if it's actually worth the effort, then untangle the mess beneath.
That's a net win in my eyes, though by the time I actually run something in production, I generally try and untangle the mess before I do. I also find it's easier to get help developers deliver something legible as sadly many of them often don't even know which packages they installed to get something running.
Listen, I'm not saying it's perfect. I specifically really don't like that Docker is basically root without Selinux (which is often turned off). I'm happy to see docker be replaced. I am however, not really interested in returning to puppet modules to handle dependencies when a container is, in my opinion, so much better.