The original conferences were about ten years ago. I am still interested in learning organisations, especially connected to ideas about quality. But the first conference was very influenced by critique and a lot of practitioner concerns got lost, in my opinion.
Without a doubt CMS has done well for academic publishing. Here is a graph based on Google Books.
The growth starts befor the time of the conferences and has continued strongly.
But a search of Google Trends in general shows no significant result.
This suggests that CMS has been an academic project that has no connection with a public. This might explain why conferences that ionvolve both academics and practitioners are rare. And rarer now than a while ago.
The mtw3 blog has some more stats on learning organisations and dynamic capabilities.