Because love is un-Islamic.
Via GMA News:
Florist Hussein came up with a simple solution to a ban on red tokens of love: he filled his window with white roses, orange irises and violet hydrangeas.
“I’ve hidden everything red in the shop, so when a religious police patrol comes along, they find nothing to complain about,” he said.
Anti-Valentine’s Day patrols by the Muttawa religious police—formally known as the Commission for the Promotion of Virtue and Prevention of Vice—started on Wednesday.
They began entering premises stocking chocolates, flowers and souvenirs to warn proprietors against selling anything red or heart-shaped and linked to the annual “infidel celebration” of matters romantic.
Saudi Arabia applies a rigorous interpretation of Islam under which the sexes are strictly segregated and any public display of affection is completely taboo.
Red roses lurk hidden in flower shop back rooms and heart-shaped chocolates are sold under the counter, but Saudis still manage to buy Valentine’s gifts and defy the religious police.
In another shop in a commercial district of the capital, an Egyptian employee said the religious police had told them not to sell heart-shaped chocolate or sweets wrapped in red paper.