I can't stand hipsters. I'm just saying, involving a video game in the mourning of a lost loved one is kind of... odd.
Love and grief both are often irrational. As is emotional energy.
Movies aren't real, but they make people cry and hold them close to their heart. Personally, I find men going crazy at a sporting event absurd, but I won't deny the accumulated bank of emotional energy it has become for them. The same is true for television series or role-playing games. It doesn't matter what the emotional energy has been banked in. The fact is, it exists for a lot of people, in a lot of different ways.
The important thing to realize is that this particular instance is not about *you*, and you don't have to understand it. And going out of your way to point out how you don't understand it is as pointless as it is tactless. The thing to do would be to show support, or don't bother saying anything at all.
My boyfriend and I have a full, rich life, and also spend wonderful moments adventuring together in this game or that. I can relate to how he might feel.