This sounds disgusting. So many of our burial traditions are a result of simple minimalistic burial. The reason people put flowers there is because if you were to just bury a body into the ground to feed the worms, the soil would become so healthy that plants that require healthy soil(like flowers) would grow there in abundance. That is where the tradition comes from. People just put the flowers there now because the casket impedes the improvement of the soil that would naturally happen from bodily decomposition if the casket weren't there.
I don't think it's disgusting. After all we don't bury bodies to feed worms but to deal with the unpleasantness of a rotting corpse and as a mark of respect for the deceased. We bring flowers as a sign of love for the person.
Different cultures and religions have different customs. My neighbour's family go together to tend granpa's grave, keeping it clean and tidy, putting flowers there and they "have a drink with him" pouring beer on his grave! being Anglican they don't give a thought to praying for him.
In other cultures, they take the body out of the tomb every 7 or so years, depending on the importance of the dead person, process with the body, singing and dancing and they re-dress the body.
Not my preference but maybe an improvement on cremation????! !? ?!?