>>512287269 (OP)
This is actually a good question. The answer is because enbakmed bodies require concrete casings to meet environmental regulations. You may blame the funeral home industry for this,
For time immemorial, people would honor their recent dead, and put them in the ground in their ancestral lands. The funeral industry changed this custom, and helped divorce people form the understanding and acceptance of death as a natural part of life. To the western mind, the subject of death is something to be avoided at all costs. Due to this, people do not have the same closure that they would if they practiced their ancient rituals. It's a shame.