And if it is sarcastic what exactly is he mocking ?

I guess that most HN readers would be unfamiliar the tools of the trade for big data and machine learning.

http://philip.greenspun.com/humor/ai.text

  The AI field has been a prolific source of hokey new
  terminology
  ...
  AI is about the same age as the rest of computing.
  ...
  If DOD spending on AI drops far enough, universities   
  like Stanford, MIT and CMU may even find the integrity
  to rid themselves of scientifically embarassing, but 
  formerly profitable, AI programs. The quality of CS 
  faculties and budgets at universities across the  
  country will continue to be diluted by the presence of
  large numbers of AI meatballs. 
  -- Gary Martins (former RAND manager)

I'm not sure if this will always be true. I think that if we move toward a sort of neural network programming (1) we won't be able to "know why" in the sense that we can explain the functions, but will instead explain programs based on output from the layers and from the relationships between variables. For instance, deep dream is a way to understand how google's image classifier is "working" (2). It's super interesting that the classifier thinks that a human arm is part of a dumbbell, for instance.

1) Maybe something like this: http://web.mit.edu/~axch/www/art.pdf.

2) http://googleresearch.blogspot.ch/2015/06/inceptionism-going...

Google is well aware of the problems of machine learning:

http://research.google.com/pubs/pub43146.html