Another thing is that with the BSDs companies can do like Sony has done, fork and keep proprietary.
With Linux being GPL, shipping a product using it means the driver code pretty much has to be released (unless you go to the lengths that Nvidia has done to keep a shim between the kernel and their GPU code).
FreeBSD has had jails for a long time and people using FreeBSD in production have been using them for a long time.
Linux just has a lot more attention.