Well, to steal a riff from Steve Jobs, milliseconds per day * days over years of use * tens/hundreds of millions of users (if you're designing the conventions for a big platform) = years or lifetimes. I'm just not convinced by the reasoning.
Yes, I've heard that reasoning over and over again and it just doesn't hold water at all for me. "Time-saving" just doesn't work at that level of minutiae.
Again, it's simply optimization where none is needed.
