Mind you Im not a doctor, but if I understand correctly inguinal hernia is on outer surface. The problems with achieving adequate depth while performing ressection are adhesions that are formed inside, between rectum/sigmoid colon and penile area. This adhesion scar tissue inside is what makes a ressection a lot more complicated, with much higher risk for possible complications. And some surgeons who dont have adequate training for such complicated ressections, will rather choose less depth instead of possibly making a mistake and causing severe complication...