I don't think it would be right to ban cremation or burial; what happens to a person's body upon their death should be a decision between them and their family (and as with most things, there is a "within reason" qualifier there).
I heard a while ago that one reason the practice of burial was adopted by early Christians was to affirm their belief in a bodily resurrection. A lot of the prevailing philosophy at the time held that the body is evil, so being a disembodied spirit would be the best state to be in. Christians believed that God made the physical body, therefore it is good, and at the last day, he will raise both the body and the soul and perfect them both. (I am hopefully not oversimplifying or interpreting too much.)
As a Christian myself, I hope for the same thing (though don't ask me how it's supposed to happen; it can only be a miracle), and I appreciate the statement the early Christians were making, so if I were to choose, I would choose to be buried rather than cremated. But I don't believe that I need to be buried in order to be resurrected-- whether I am buried or cremated or eaten by a tiger or blown out into space, I will be just as dead. It would be pretty illogical to say "God can raise a person from the dead, but only if their remains are in one place. Otherwise, it's just too hard." As if raising a person from the dead is the easy part? (The other possibility I might consider would be donating my body to science, if there's some chance that studying it could be used to develop medicine to help others.)
Oh, sorry. That's probably a very weird digression. But it's at least an example of how beliefs about what should be done with a person's remains after death are very personal. It would be wrong for me to try to force everyone to do the same thing as me if they are hurting no one by their actions. There are times when people are required to cremate a body because the person had a dangerous disease that must be destroyed so there is no chance of contagion; that's a case of protecting others. But in most cases? It should be a personal decision.