Because Valentine’s Day is not an Islamic observance. From Reuters, with thanks to the Constantinopolitan Irredentist:
RIYADH, Saudi Arabia (Reuters) – Saudi Arabia’s morality police are on the scent of illicit red roses as part of a clampdown on would-be St Valentine’s lovers in the strict Muslim kingdom.
The Committee for the Promotion of Virtue and Prevention of Vice, Saudi Arabia’s powerful religious vigilantes, have banned shops from selling any red flowers in the run-up to February 14.