Say you've got a 10 new joiners per week at your high-turnover packing factory, and a sign outside the admin office that says "Paychecks are distributed bi-weekly".
Maybe typically 5 of them have had a job before in the area, 3 have had a job elsewhere and 2 have never had a job. Not all of them have the same level of education.
How many will misunderstand your sign? Might any of those misunderstandings about money cause problems for people?
Considering the comparitive cost of writing the sign as "every two weeks", and the reduction in potential confusion, it seems like a no-brainer to write it that way.
