Mozilla does this from time to time for really egregious cases [1]. There is a high cost to staging the block. If the author is known there is a delay to try to get the author to ship a fix [2]. If it is unknown then the block can proceed rather quickly but the cost of changing the extension to avoid the block is usually cheap [3].

[1] https://addons.mozilla.org/en-US/firefox/blocked/ [2] https://bugzilla.mozilla.org/show_bug.cgi?id=527135 [3] https://bugzilla.mozilla.org/show_bug.cgi?id=937405

You can still use Dev Edition or Nightly with an about:config pref set.