tldr; some sub-sites are justified, others are just a pain.

I believe so, especially when you consider that revenue is generated via ads, and the more visits to a *single* SE site the better. 

I tried to get the good folks over at RPi.SE to see that [their questions](https://raspberrypi.meta.stackexchange.com/questions/370/should-this-site-merge-with-the-embedded-programming-design-proposal) fit happily inside of a linux SE and a [Embedded electronics site]() such as that proposal I just linked to, but as you can see it wasn't happily received. From what I gather they can't see past the fact that their site is in beta and the other one isn't (although that will change soon).

Also, The top answer [here](https://area51.meta.stackexchange.com/questions/12432/why-is-arduino-a-proposal-separate-from-embedded-programming-and-design) indicates that those proposing sites aren't familiar with the intended purpose of the sites, to attract *experts* and *then* n00bs, not keep the site for n00bs. Even for a site for rookie programmers such as Arduino and/or RPi, it would hugely benefit them to have people with higher level knowledge in those fields visiting that site, and that probably won't happen. 

A snippet of my answer from the above question:

>In general though, it seems a lot of cliques just want their own 'board', but don't really understand what goes into making a site, and also don't understand why common interests should be merged into a single site. SO is really a shining example: There is pretty much every programming language under the sun in scope on SO, both compiled and interpreted languages. There isn't a separate site for python programmers, or windows programmers vs linux programmers, scripters, or arduino programmers, etc. If it's a programming question it goes on SO. C or C++ has a large enough following to warrant its own site, but that doesn't mean it should, for way too many reasons to list. Suffice it to say that

>1. ***Common interests should stick together*** - Programming concepts are fundamentally the same across all languages, even if syntax is different. Thus, someone with expertise in a different language could answer your question, but may never even see your question if it's on some niche site.

>2. ***A broader question scope draws more traffic*** - more traffic equals more Q&A and more search engine results, which equals better ad $, which equals the possibility of a sustained site and not a killed beta.