Participation in meta will always be something for a minority of users. That does not mean that it's not somewhat representative from the greater community. It's a vocal, self-selected minority that chooses to make itself heard and express their opinions and views about the rules, policies and well-being of the sites they participate in.
A slightly greater participation could be achieved, but the certain aspects of the "meta" should be updated / changed; since I believe they are no longer really fit for purpose.
To work in the long term, there should also be a retooling of voting. Votes have overloaded meanings in Meta, where a custom has developed to vote up an down to signal "disagreement".
Which is relatively effective, if crude. But coupled with the facts that these sites have much lower post traffic relative to their userbase, and that (MSE excepted) votes do not affect reputation, vote counts can soar very highly or sink
That not only can be really tough on newer meta users (and for old hands as well, even if they know how things can be), but makes scores less useful and expressive than on the main sites.
Also, communication with staff can get really weird with our voting system. For example, when answers to support questions get downvoted into oblivion because many in the community disagree with policies that are very likely not in the hands of the one answering the question.
Something different should be tried, since the simply voting mechanism that works so well in the main sites is rather lacking on the meta sites.
Additionally, meta serves (or used to serve) more roles than one. It is used for community building and shaping. Community sourced support. A living record of how and why many of each site's policies came to be or not, and continued discussion of further policy evolution.
But as feature suggestion / bug tracking tool... it sucks. A specialized platform should be used for this. I think the company is well aware of it, and hopefully some day they'll get there and have a solution that's open enough, allows for a useful amount of community participation, permits to have some sort of transparency on the development roadmap... and it's not horrible. I can dream.
And for company wide announcements it's poor as well. Most users who visit a meta will visit their meta, not MSE. So publishing this kind of thing here is pointless. And on top of that, most announcements really do not benefit from the Q&A format. They are announcements, not questions. And "answers" serve little purpose there.
The blog is not nice either, because of how divorced it is from the community. The kind of thing they are publishing in the blog should probably happen in meta, but for that to be really possible and productive, changes need to be made to the supporting software.
Easy: Promote it more, and more often.
Participation will always be minoritary, which makes sense. Logically, the vast majority of users will be interested in using the site, not in discussing how the site should be used, moderated and governed.
But when, for example, moderator elections are held, promotion of the event and the meta-related features are much more heavily involved, and thus I would imagine we see spikes in participation.
We used to have "hot in meta" that drove additional traffic to meta, but it was removed because of the perception of how things went on in meta. I believe it should be added back, but that also changes in the tooling for meta should be made to help have healthier interactions.