For good on-topic questions, it it completely irrelevant if they are posted here directly or if they are imported. In the past, we have observed that indeed imported questions can attract new nice answers here too. And as we have disabled the feature of accepting answers, it is not even a drawback if the original asker of the question himself is not here (yet).
So I disagree with making a superficial additional difference between imported and native posts. The relevance and quality of a question does really not depend on this. When looking at the question list, people can just click and read questions (and their answers) they are interested in from looking at the title, and the ones who really care for some reason can see if a post is imported from the presence or absence of the attribution line.
Of course we hope that the rate of natively posted questions will increase in the course of time, but for this we have to be a bit patient. Happily we to not have to fullfill any externally prescribed activity criteria ...