What does "too much can be made of X" mean?
Source and context:
Too much can be made of statistics, of that there can be little doubt, but the Colback conundrum is an intriguing one.
TO "make much of" something is to see it as being important, significant, relevant, reliable, or some such. For example, if you said, "Jack made much of the job applicant's two college degrees", that would mean that he thought that the college degrees were very important and relevant.
To "make too much of" something is to give it more importance than it deserves. (Of course this could be a matter of opinion.)
So the quoted sentence is saying that people sometimes give more importance or significance to statistics than they should.