Common latchpins with 74HC595 Shift Register

How about if the data comes from user or sensor input, but each sensor only relates to one shift registers outputs sometimes, but not always. A benefit of not changing the data in some registers, is that you dont have to keep track of what was there, but if you over write the data, then you could accidentally change it.

It is like trying to solve a problem, when you dont have a problem. What Im thinking is that there might be some strange circumstances where this useful. For all I know, it could turn out to be very useful for something.