I think where shorter matters is with mobile clients.

No mobile platform is really secure. You don't want to keep a lot in a mobile wallet, it is better to load your mobile wallet when you are going out with intent to spend but otherwise (just like a leather wallet) don't keep a lot in it. Unless you are only going to spend in one place, or you transfer to it using lots of outputs, confirmation time impacts when your change address from Merchant A is available to buy something from Merchant B.

It also matters for things like phonesex, but that's a different topic.