It wasn't a problem that the Magic Grid Core was swallowing the divine energy—that was Roland's goal.
However, it wasn't good that his virtual Divine Spark was converting to the Brutalization Divine Spark.
The Brutalization Divine Spark was evil. If he absorbed that, he would probably become an Evil God.
Of course, some might argue that power was neither good nor evil and what mattered was the person who used it.
That argument was correct in a way.
However, it did not apply to every situation.
For example, poppy, as a medicine, could cure a lot of diseases.
But everybody knew the consequence of absorbing it on a large scale.
The Brutalization Divine Spark, on the other hand, was like methamphetamine, which was much more tempting than poppy.