In Edward Nelson’s (2007) review of the book 18 Unconventional Essays on the Nature of Mathematics (American Mathematical Monthly, vol. 114, pp. 843–848), he tries to answer the question in the title.
We [mathematicians] are no respecters of persons (in that curious phrase that means we do respect persons but pay little attention to the trappings of age, position, or prestige), we take equal delight in fierce competition and collaborative effort, and we are quick to say “I was wrong.” Perhaps some of us know an exception that proves the rule, but by and large I speak sooth, especially when one compares mathematicians to our colleagues in the humanities.
How does one explain that we are so lovable? Is there something in the nature of mathematics that attracts gentle souls? Possibly, but another explanation is more convincing. We are singularly blessed in that the worth of a mathematical work is judged largely by whether the proof is correct, and this is something on which we all agree (eventually), despite the fact that we may have divergent views on the nature of mathematics […]. This is a singular fact. In art, projection of personality may prevail; in the humanities, the power of position may prevail; in science, the prevailing fad may prevent the publication even of excellent work—but we are extraordinarily fortunate that in our field none of this matters.