In many games which can be modded the second thing that modders tend to add after the prequisite nude mod are weapons. Specifically, guns. If it's a fantasy game, first the flintlocks, then the muskets (what is this exploding crossbow?). If it's a modern game, more guns. If it's a sci-fi game, modern archetypes of guns dressed up and made pretty. At what point does the gun porn become excessive? I mean, there's often a lot of work that goes into transforming a real-world weapon into it's simulated counterpart, but when a player is faced with umpty-tumpty assault rifles to choose from what seems to happen a lot of the time is that the list gets whittled down very quickly to the "obvious" choice, and modders may as well have not bothered. There's often just too much overlap.
Now, I do recognise serious gun porn can work in the games' favour. Take Borderlands, for example. That has gun porn coming out the wazoo, but it builds itself around the "ditch it" mentality. Many mods don't work like that - the modder wants you to use the guns developed. Not drop them when the next shiny toy comes along! Can there be too many guns?