Because his stated motivation was snobbery. To quote wikipedia

Dawson said that he acted to preserve the King’s dignity, to prevent further strain on the family, and so that the King’s death at 11:55 p.m. could be announced in the morning edition of The Times newspaper rather than “less appropriate … evening journals”.[1][22] To make doubly sure that this would happen Dawson telephoned his wife in London asking her to let The Times know when the announcement was imminent.[5]