Why there is no fragrance in flowers of all varieties, even roses?

A lot of flowers have been bred for their beauty, not their scent. Old fashioned varieties (heirloom) still have their scent.

I agree with all the above, in order to keep coming up with new varieties the new hybrids don't have scents. I wish they would have left well enough alone. I miss the scents of flowers that used to be present in gardens.

I think when breeders have the challenge to make a plant more resistant to disease or pests, or to have larger longer lasting blooms, the fragrance will be bred out of them. Some people with allergies to flowers or those allergic to bee stings appreciate having the scentless varieties. Growing up I saw a friend's father almost die from a bee sting-it was scary.