I feel (entirely biasedly) that this proposal seems to miss a lot of context and *community culture*.

First and formost, most of these sites are *successful* by Stack Exchange standards and have met all the requirements for graduation. Where they didn't, they still have large *self sustaining* communities capable of answering questions. 

Lets start with 2/3rd of the trilogy - Serverfault and Superuser. Superuser's all about the 'pet systems' individual systems, stuff you run at home. I prefer serverfault for 'big picture' things - infrastructure, servers and such. Something like [this][1] belongs on SF as does anything about *running* IT and services. 

Askubuntu is a Q&A site *officially* supported by Ubuntu, and was an early and rather successful experiment that didn't *quite* get repeated. It has its own vibrant community and serves the wider ubuntu community pretty well.

U&L is interesting. It *does* fit quite neatly into the scope SU and SF have but in many cases *the community* there's really good at *very difficult* problems. SU's pretty broad, and sometimes you need *depth*. You're going to have to exercise the [peewee herman rule][2] in deciding where to go.

I've never been to ask different, but at the very least, while they intersect with our scope, they cover things outside ours (like iphones and apple watches) that arn't served elsewhere and probably have the same sort of depth in their subject matter U&L would have

I'd like to address a few statements made in the question specifically. 

> Some of those sites don't get a lot of traffic

I'd have to get a CM or other mods to confirm but these are sites that have a *pretty* vibrant community from what I've seen in their main chatrooms and web frequency of new questions.

SU gets roughly 500 000 to 800 000 visits a day  

> non-programming

That's ... kinda narrow minded. We cover hardware to an extent (which U&L and the others don't). While *historically* we've had a single, monolitihic site for programming, it does not necessarily mean that model works everywhere. As someone who generally dosen't code, but has spent time in other parts of the IT industry, there's so much more to computers than coding.

So, while I don't speak for Stack Exchange as a company - its unlikely to happen. And if it does, the communities involved will be poorer for it.  




  [1]: http://serverfault.com/questions/791974/is-there-a-best-placement-of-hot-hardware-in-a-rack-to-maximize-convection-cooli/791976#791976
  [2]: https://stackoverflow.blog/2010/11/the-pee-wee-herman-rule/