This is a weird metric. Somehow being on a random injury list (which apprently doesn't even mean that Gibson was not available to play) is a more important than games actually played or long term injuries. By your logic, a guy who goes on the list once - the first day of the season - and stays on the list the entire season is less injury prone than a player who has two listed injuries, one day each.
I have no idea how the "injury list" is maintained by that website. It appears the NHL has no rules requiring disclosure of injuries. So the data is not consistent.
Injury report: When do professional sports teams have to reveal a player's status?.
Show your work - what was the average times on the list for a goalie? What was the average number of days on the list for goalies? I don't think you have any reliable data that speaks to that.
Gibson was injury plagued early in his career. The last 3-5 years, he's played a ton of games and not missed extended time. That's a pretty good track record, particularly when you consider the abuse he's taken from the ducks terrible play in front of him (e.g., facing the most shots in league history).