For me, and I'm sure many contributors, the key thing on any message board is to get a response to your issue.
When I was having my driveway done and trying to work out what I needed, I posted in Mumsnet Property but people didn't have the specialist/technical knowledge.
I found a site about Paving which had a forum and asked my question there.
That site also had a message board which included TV, gardening - lots of general stuff the professional paving people might also have in their lives.
The site was 'meant' for driveway/construction professionals but they were open to helping diyers.
When I've got car issues, I often look/post on Pistonheads.
This very big message board also has all of the same forums as Mumsnet. I suppose it was originally attractive to men (stereotypically) and that's still reflected in a general sense in the type of responses you get and the focus of the knowledge on the board.
I've also posted on Gardening forums and Alzheiner's forums which have all also had the 'general life' TV etc forums which Mumsnet has.
The reason I often use Mumsnet over the more 'specialist' forum is because sometimes I need an answer to a question which a car, driveway or dementia specialist won't necessarily be the best person to answer.
Sometimes those boards attract a kind of user whose specialist interests are mainly all they're interested in and I wouldn't get an answer to a more 'general life' question.
However, on Mumsnet, becaue there is no 'specialist' knowedge required - ie. all you have to have been able to do is pull someone, and get knocked up (it's not Mastermind! being glib!) - the range of knowledge can be very broad - most people can fuck but not everyone can lay a driveway and so on.
So, when I want to buy a washing machine, or get an answer to a very general question about what's it like to live in Catford - Mumsnet is the place to be!
I wouldn't get the broad response I want, from Mens Healthers, or Dementia experts, or Pavers or Gardeners - so if I broaden my sample population out to anyone who can shag or even just, anyone! -( we've all had parents) - I have a better chance of getting a response.
That's why I sometimes use Mumsnet over specialist boards - so in the end - to answer the OP - being a 'parent' does not make one 'special' - it's just a normal thing made 'special' (by whom and why I'd be interested in knowing?) - it's not a specialist subject, if we're not all parents then we've all had them - it means you might have a place to live and a car and a job and might have (or want) some general knowledge that could be useful to others.