Even I have tried reading that thread.. But couldn't go beyond a limit. I was surprised to know from there that even Asivad got rejected once for proof of funds!
Common reasons I came across are:
1) Degree copy missing
2) Incorrect PCC submission/missing PCC without LOE
3) Unjustifiable proof of funds
4) I have seen others quote this - missing ECA, missing IELTS - never read anyone posting directly
5) Reference letter does not confirm to NOC lead statements
6) Black & white scans
7) Missing passport pages
8) Hiding/Missing a past visa refusal