In the past I tried ground level feeders, this creates some issues. The dogs like to get into them.
Butterflies do not like strong wind or deep pools of water, especially when drinking or feeding.
They do like colors and a calm place to drink.
By using a movable pot with a colorful shallow plate, it allows me to move the feeder around and is a perfect drinking container.
When starting my seeds for the attraction flowers, I can put the pots in the best spot for growing in the sun. Once my flowers have established themselves - I can move the pot to a less windy spot. In my yard, the wind can come in different directions. So it is nice to be able to move the flowers with the feeder about the yard.
By elevating the feeder it allows a greater amount of flowers to grow / climb in one concentrated area.
Plus it is easy on my back to refill the plate feeder with water. I use a sponge to retain the water. Even with a sponge, the feeder dries up quickly.
Well that is my reasoning for the design.