Re: How To Disable BoddyPress on Just one Site of a Multisite Project
And you know that even network activated, all users have their BP profile on the main site?
BuddyPress is network-wide, not blog specific.
“One way you can prevent BP in main site or secondary site from importing data from all sites is by marking e.g. My Blog in Settings > Permalnks – “I would like to block search engines, but allow normal visitors” or even choose additional options with https://wordpress.org/extend/plugins/more-privacy-options/”
Which blocks search engines as well. 
Better off to mark the blog as mature instead.
