Param Purush had 16 sons But why did He give the Souls to the bad Son alone?

The Jivas continued to move about in a joyful manner in Amarlok. After a long time the 5th son, Niranjan, began to meditate. He meditated on Param Purush for a period of 70 Yugas. The latter was pleased with his worship and asked the reason behind worshiping so hard. Niranjan said that he wanted to have some abode of his own. Param Purush gave him Mansrovar (a continent of Amarlok ). Niranjan was pleased to have it. He began to live there in a joyful manner. However, once again, he began to worship Param Purush. He did so again for a period of 70 Yugas.
Param Purush was pleased and asked what he
wanted.

Itna Thanv Na Mohi Suhai  
Abb Mohi Baksi Deh-Hu Thakurai  
Kai Mohi Dehu Lok Adhikara  
Kai Mohi Dehu Desh Ik Neyara  

Niranjan said that he was not pleased with that much. Either He should give him Amarlok or a rare kind of Loka where he could have his full sway.
At this, Param Purush told him that his elder brother Kooram had with him a seed of 5 material elements in a subtle form. He should go to him and beg from him that very seed.
With that he should create 3 Lokas in Shunya (space). Also, he could rule there for a period of 17 Asankhya Chaukri Yugas.
Niranja went to Kooram but instead of requesting him to give him the seed of 5 material elements and three gunas, he took it forcibly from him in a manner one squeezes out blood from someone’s body. Kooram Ji remained calm and peaceful. But he asked Param Purush as to what kind of a devil He had sent to him. He had robbed him of the seed of 5 material elements in a forceful manner. Param Purush asked him to remain calm saying he (Niranjan)was his younger brother.
Param Purush thought as to what a kind of Niranjan
had been created.
With the seed of 5 material elements Niranjan created the 5 material elements (water, fire, air, earth and sky). Also, he created 49 crore Yojan Earth, Sun, Moon, Stars, Seven Patals etc. He remained in Shunya for some time. Nevertheless, it was a lifeless universe as there were no Beings. Niranjan thought that the universe without beings was not worth living. As such, he again worshipped for a period of 64 Yugas.
Param Purush asked as to what more he wanted.
Niranjan said—

Dee Jae Khet Beej Nij Sara  

Niranjan prayed that he had created the 3 Lokas but there were no Jivas to rule over. He prayed to Him to kindly give some hansas to him.
Then Param Purush desired and created a girl (Adhya Shakti) with 8 arms. She offered salutations to Him and asked as to why she had been created. Giving her infinite number of souls, Param Purush said—
O daughter! Niranjan is in Mansrovar. He has created the 3 Lokas in Shunya. Go to him and help him in giving birth to a true and real universe. That is to say, the universe had to be created like the one in Amarlok. It was a clear message that the souls hadn’t to be imprisoned in the bodily cages.