[nbouscal]

The word "just" feels awfully out of place in this context. If you were doing some kind of broad-based polling of public opinion, of course you'd want a bigger sample size, but 29 of the top 100 researchers in a field sounds like a hell of a good sample to me, and well worth listening to.

[icebraining]

If they were 29 random researchers, I'd agree, but since they were voluntarily selected, not really. They try to check if the sample is biased, but it's not convincing.