Personally, the main reason I haven't participated more in meta is that there isn't much activity on meta. I realize that's somewhat of a catch-22. However, the low activity isn't necessarily entirely negative.
A lot of meta activity on other SE sites is debate and contention. Half the community wants a certain type of question banned, the other half wants more of those questions. People whining about their questions getting unfairly closed, often not without good reason. Things like that. Compared to other SE sites, Parenting.SE is a much friendlier site with topicality that is fairly clear cut, so naturally there won't be as much debate.
On the other hand, compared to other non-StackExchange sites, especially parenting sites, the StackExchange format seems a little cold. Chatty back and forth discussion isn't encouraged, your questions get edited by strangers, and we have stricter standards about staying on topic, not creating duplicates, etc. The community moderated model is new to a lot of people, and trying to figure out if something belongs on meta, main, or chat can be confusing.
That makes for higher quality questions and answers, but is also less inviting. I'm not sure how we can improve in that area other than continuing to politely and gently point newbies in the right direction. Perhaps making the tour more prominent to first-time visitors would help.