*"in this one, I’m with you… using Library folder is just plain wrong." *
I will have to agree too. I would expect the launcher to put them in the same folder as launcher or a folder than user chooses. I am also a big hater of shared libraries and their shared folders. Uninstalling them is a pain in the ass and generally you should not touch them unless you know exactly what you doing. I can see the reason behind big libraries that are hundreds of megabytes. But in the age of terabytes, megabytes/ kilobytes shared libraries make no sense to me at all.