Flowers have evolved to look, smell and taste in a way that attracts pollinators, some of whom also happen to see colors and appreciate sweet things much like we do. While we, humans, find many wild flowers attractive because we share some of our preferences with their pollinators, some times [1] it's painfully clear that we're not the target audience. On the other hand, domesticated flowers you can buy as at a flower shop today were bred for centuries specifically to better satisfy human tastes, so it's no wonder we like them so much.

[1] https://en.wikipedia.org/wiki/Carrion_flower