I had a post all written up trying to discus this AFK timer issue, but apparently it was over the character limit so I guess I'll do this dirty way.

There's a hard cap on connections per world. It sucks.

AFK characters don't take up a lot of CPU: True. They do take up another resource: Memory. A connected character has to be ready to move when input is given, so they're kept either in active memory (RAM) or some kind of cache on a storage drive. This maybe the upgrade to the data centers SE is looking at.

As time goes on from a server restart more people log in and remain AFK so they can avoid the frustration of logging in. This causes the ratio of AFK to active players to rise over time. It's not a function of maliciousness, just avoidance.

This growing ratio is why people want an idle time out, it would keep the ratio under control. So does upgrading the data centers. Upgrading the data centers maybe ultimately better as it actually increases the hard connection cap.