Only Apple can make a BSD base system , what do you mean ? Systems like OpenBSD , NetBSD and DragonflyBSD started as a FreeBSD fork.As for me it is not. Sure, some very marginal users do not need much from PC and can use this crap as desktop. I don't see any reason to force me to use this crap when there are better solutions available and they come with sources as well. So I can learn them, change them and build them. If I want or need to. And no vendor lock-in. But why Linux? Linux takes several times less times for system management than any BSDs/windows/etc. I've attempted to use FreeBSD on one of my servers and it proven to be real nightmare. There is even no real package management system in place. In Linux it's norm and it makes system management much more pleasant task. Which also takes much less of my time than it would be otherwise.
Oh, Netflix? Those DRM-inclined nuts who also require silverlight M$ crap to play their content? Oh, now answer quickly: can you use Netflix services in your "adequate" BSD desktop, then? (and then BSD guys wonder why other ppl consider them proprietary footpads).
Oh, another proprietary nuts. And of course no full source for MacOS X. And absolutely no source for iOS. So with Liunx you can try to make your phone based on Linux stack if you want to. With BSDs only Apple can. That's where we can see how BSD "freedom" differs from GPL freedom...
So, can I grab the source, learn it, change it, rebuild it and use it on Juniper hardware if I own one? No? Such a pity. BSD "freedom" strikes again. It turns out only Juniper haves rights and freedoms. Not their customers. Since I'm not Juniper, I see absolutely no reasons to welcome this approach. Especially granted the fact it's customer who pays money for everything. So this scheme does not looks fair to say the least.
And Linux just powers biggest, most successful startups (Google and Facebook to name a two), most of TOP500 supercomputers, millions of phones, routers, servers and so on. And even gaming industry started looking at it. So it's finally getting considered by people as OS suitable for desktops. Not something that BSDs could afford. Ironically, Linux took several percents of market in the web. BSDs had 10 more years to get there. Yet they're used thousands times less than Linux. This definitely indicates BSDs are inconvenient to use and/or lack many features.