Because you haven't maintained the 'positive question record' the badge requires (see here).
Clicking on the badge actually informs you of this ("need positive question record"):
What constitutes a positive question record is the following:
(total questions - negative questions - closed - deleted)/total questions ≥ 0.5
Which gives you a score of (19 - 6 - 6)/19 ≈ 0.37
So you need three more positive questions (and no negatively received ones), and you will receive the badge.
It is a little strange that the counter does not take that sequence into account, however, but this issue has already been raised on Meta.