Take the number of users in the field, A, multiply by the probable rate encountering this issue, B, multiply by the average time wasted working around the issue

Take the number of users in the field, A, multiply by the probable rate encountering this issue, B, multiply by the average time wasted working around the issue, C. A times B times C equals X. If X is less than the time to make a fix, we don't do one*. (not speaking officially for any oss I may contribute to, just found the Fight Club resemblance fun)