Actually, I always put it down to Ianto having Things He's Responsible For and that those color his world view even in the midst of the hub collapsing:

Ianto is responsible for coffee procurement.
Ianto is responsible for the care and feeding of Myfanwy.
Ianto is responsible for the care and feeding of Captain Jack Harkness.
Ianto is responsible for making sure Jack has his coat when he wants it.
...etc.