Ask HN: Why are AI startups the least funded of all sectors?

Reading through this blog http://blog.letsventure.com/lv-data/q1-report-fy-17-18/

I assumed they would be the hottest sectors to invest in.

From a investor perspective I guess it's because it's the least likely to return 20x the investment and we have seen this practically in our experience.

Are there any other reasons for this sector to languish?