Those jets were already being used, the flowers are just using what capacity was there. It's not like FedEx/UPS/etc said we need to increase capacity for flowers. Growers took advantage of a service that was there to increase their sales while also making them available to people that would ordinarly not be able to have them.

Do you like fresh fruit in the winter? Do you like bananas? All of these things are not normal for most people in northern latitudes, yet we all now get to enjoy them.