I think IRL you find coaches who are aggressive in other areas of the field, but who are reluctant to turn down a virtually-sure PAT in favor of a less-certain two-point conversion. I believe their own players, their owners, the fans and the media would tend to turn against hyper-aggressive coaches after a single loss - and coaches tend to value their own job security.
In game, I'm pretty confident I could convert well over 50% on 2PCs - but I'm playing against an AI with limited goal-line defense savvy, and I have a good list of goal-line plays that I run that get me what I want. Like points.
