The Islamic burial is almost identical to Jewish burial. They both adhere to the same principals and follow the same ideas. It is nothing unique to Islam. Other religions and cultures also perform simple and straightforward burial rites.

Cremation is the the best, most efficient way to transfer the deceased's atoms back into nature. It is clean and poetic. There is no need to waste acres upon acres of land for bodies just to slowly decompose underground. The persons who the deceased were are gone forever. Their bodies and flesh will also be gone given enough time. If you dig up a year old dead body from an Islamic grave it will be a horrible thing to behold. The dead body will hold on to no dignity.