I guess it depends where exactly you set the threshold. Require too much knowledge and the pool of opinions, and the diversity of the sources of those opinions, will be too small (ie, just "AGI ameteurs"). On the other hand, the minimum amount of research required to properly understand the AGI issue is substantial, and if someone demonstrates a serious lack of understanding, such as claiming that AI will never be able to do something that narrow AIs can do already, then I have no problem excluding their opinion.