1. mu-plugins have been around since I began working with wordpressMU several years ago
2. I share what I use, the way I use it.
3. Even SuperAdmin access can’t disable the privacy plugin unless they also have ftp access.
4. And, well, lazy is probably the best reason.
What I should do is put “Network: true” in the header of the plugin and it would only allow for Network Activation direct from the WP plugin repo, but the plugin would still expect to work if the site was a non network site. I haven’t bothered to code/test the plugin for privacy options for both both single wp and network wp. So I’ve left it as is.