This is a copy of my answer to Camil Staps' copy of this question over on Robotics
Although I am open to the idea, my current preference is against a mega-merge of Arduino, Raspberry Pi, Embedded and Robotics.
As I said in my answer to Embedded Systems StackExchange (suggesting merging Embedded and Robotics):
Having had a look at the questions on the site and only been able to identify one, I don't think that any kind of merge would be appropriate, but we should certainly suggest (using that answer) that any questions which are on topic here be migrated here.
I think that part of the problem here is that people seem to think that there is something wrong with a site which is asking good questions, getting good answers and accumulating page views and users, but hasn't yet graduated.
In fact, there is nothing wrong with this situation, and Stack Exchange have finally woken up to the idea that some small, niche sites will never reach graduation criteria, but equally will never disappear, and that we need to handle this state of 'perpetual betaperpetual beta' more gracefully.
See Graduation, site closure, and a clearer outlook on the health of SE sitesGraduation, site closure, and a clearer outlook on the health of SE sites and Should we rename or remove the "beta" label?Should we rename or remove the "beta" label?
As I mentioned in a comment on Andrew's answer to Closing this [Embedded] site on Friday, August 14
The problem is that merging four sites with four scopes and four communities risks destroying all four. In particular, a clash of cultures and alienation of existing users is a big risk. Ultimately any stack exchange site needs to stand on it's own and now that permanent beta is the rule rather than the exception, we have to accept that small workable vertical sites may well be better than broader based, artificial amalgams. In essence, a strong & growing community, even if it is small, is preferable to a weak diminishing one.
In the long term, I hope that perpetual beta sites will start to get some of the benefits of graduated sitessome of the benefits of graduated sites, even if it isn't worth Stack Exchange spending time and development resources on a custom site design.