what was the reason/explanation of rejection IRCC gave to him?Can I have more than one Express Entry profile?
No. You may only have one profile at a time. This is set out in Canada’s immigration law.
Creating more than one profile will not give you a better chance at being invited or allow you to be invited under a different program.
Refer: https://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=864&top=29
Also, I heard a case a person had two active profiles and he got ITA for both and later his PR was rejected.