One other thing that is missing here is that Firefox was trying (and still is) too much to be an "app store" and "sandbox" for extensions. This is not what we should be expecting of a browser, and again goes back to another point someone else made in this discussion is that Firefox is chasing "huge" marketshare instead of focusing on its core and growing organically from there.
What that metric-chasing meant is having their extension store spammed with useless extensions. I think that extension-count was a mistaken metric to chase, and no wonder they felt overwhelmed with trying to support spam-level amounts of extensions.
At it's core, I think this entire debate boils down to "who is responsible if an extension breaks the browser or some other extension". A relatively small set of "complex" or "tightly integrated" extensions that enhance and extend Firefox's behavior is a good spot to be in. Rather than what we have now where all the "interesting" browser extension points are not available to the extensions to modify and we have a metric tonne of copy-paste-similar extensions that are hard to discover.
I've never seen Mozilla promoting the number of available extensions, and I've never heard that it's a significant metric they track internally. The addons site highlights a relatively small number of popular extensions, with some categories (e.g. password managers).
The blog post describes how Firefox tried to focus on its 'core' - assuming you mean people heavily invested in XUL add-ons - for years before they eventually decided it was a road to nowhere.
What that metric-chasing meant is having their extension store spammed with useless extensions. I think that extension-count was a mistaken metric to chase, and no wonder they felt overwhelmed with trying to support spam-level amounts of extensions.
At it's core, I think this entire debate boils down to "who is responsible if an extension breaks the browser or some other extension". A relatively small set of "complex" or "tightly integrated" extensions that enhance and extend Firefox's behavior is a good spot to be in. Rather than what we have now where all the "interesting" browser extension points are not available to the extensions to modify and we have a metric tonne of copy-paste-similar extensions that are hard to discover.