401(k) in paycheck deposit: the rare exception is pre-selected default

HE

Every year from January through March, I have to select for every single paycheck that's deposited that the 401(k) contribution is for the current year. Why? Because the previous year is preselected.

Now - yes, you can still contribute to the prior year's 401(k). But realistically, 99.999% of paychecks have a 401(k) contribution that counts for the CURRENT year even in January. Why in the world can't that be the default???