jrburke/backbone — comment on commit 57c2029117649452c6cf4d3337e03f5d52bb8331
File: backbone.js line 1163
By jdalton:

pointing to other weak inferences doesn't make a good argument for continuing the poor check. The `require` check is so that it doesn't incorrectly fall to the CommonJS fork if there is only some non-undefined exports value, which can happen in some browsers if an element has an id="exports".