Unnecessary shifts in point of view between first person (I, we), second person (you), and third person (he, she, it, one, or they) or between singular and plural can be very confusing to readers.
Is the writer making a general statement or giving advice to someone? Eliminating the shift eliminates this confusion.
Many shifts in number are actually problems with pronoun-
INCONSISTENT | A patient should be able to talk to their doctor. |
REVISED | Patients should be able to talk to their doctors. |
REVISED | A patient should be able to talk to his or her doctor. |