POS is made for one purpuse only, and that is getting early adopters rich.
I think this isn't true. Some purposes of Peercoin are covered in the video in the OP. However, in a general sense, all cryptocurrency benefits early adopters.
I agree that there are some negative issues on POW, but it can be fixed/changed/whatever.
This is extremely, extremely unlikely. Bitcoin is quickly reaching the point where it will never be "changed" again. Too many players would have to agree to update their software, which simply wouldn't happen unless there were some emergency.