As someone who has been using FreeBSD professionally since 1998, and built the first VPS provider on it[1] and then built all of rsync.net on it, I am a huge proponent of FreeBSD.
However I (and others) have been frustrated for years by the culture of new and shiny that has displaced a culture of stability and long term support.
Rather than rehash it all here, let me suggest that if you are interested, you may read this mailing list posting:
http://lists.freebsd.org/pipermail/freebsd-hackers/2012-Janu...
... which I wrote in January 2012. Much of it remains true today. That being said, when we reworked the rsync.net platform from the ground up in late 2012, we did indeed go forward with FreeBSD.
[1] JohnCompanies "Server Instances", based on FreeBSD jail, were made available in Fall of 2001. A year or so later the world settled on "Virtual Private Server" as the de facto descriptor.