Currently there are a total of 3,749 questions on this site. On SO there are 2,166 questions tagged "reverse-engineering" and on Security.SE there are 122 questions tagged "reverse-engineering". Not all are focused specifically on RE but quite a few are. Here are some examples:
From SO:
Is it possible to extract function signatures from object files?
Unable to set breakpoints in gdbserver via IDA Reading from already open COM (serial) port?
protect python code from reverse engineering
From Security.SE:
Identification of TPM accesses in UEFI firmware
Exploitation: EIP refuse to jump to the stack although it's executable
Volatility Plug-ins to investigate packed exe files
I've been using this site since roughly December 2016, so I'm not exactly a grizzled veteran, but these exemplars strike me as on topic and focused on or directly involving RE concepts.
I took a look at this question from 2013 about the same kind of thing: Is it possible to migrate a question from other stackexchange sites to Reverse Engineering?
This site has been in beta for 1448 days now and has unquestionably proficient moderators and an enthusiastic and knowledgeable core group of users. The idea that this site is not "well established" simply because it's still in beta strikes me as laughable (unless I am misunderstanding what it means for a site to be "well established"). The number one problem seems to be getting more people to ask more questions here.
Here is my question: given that questions from other sites cannot be migrated to a site in beta (like this one), how can the number 1 factor keeping this site in beta - the low number of questions per day - be addressed? It seems like a chicken-and-egg problem: this site needs more questions to get out of beta, but people do not know about this site and so ask on another site, depriving this site of needed traffic (and the person asking an RE question a good answer), and then the question can't be migrated here, keeping the site in beta. Furthermore, due to its technical nature RE is never going be as popular as something more accessible like Bicycles or Worldbuilding.
Others and myself have commented on people's questions, telling them directly that it would be good idea to ask a RE question here rather than SO or wherever, but it does not seem to do any good. Personally I believe that if a question is on topic for this site and in unanswered, it should be allowed for that question to be migrated here, now that it is 2017 and this site is 4 years old.