"...an infrared switch would have no such delay because it’s optical, not physical."
It may not be mechanical, but it's still physical. If it exists, that is.
My first thought was that this is nit picking. But, then it occurred to me that certain issues, like de-bouncing (or equivalent filtering) must still be done for optical, as there's surely some noise you'd want to remove. As the switch ages and wears (and dust and grime begin to accumulate), the importance of this filtering will grow.
That said, I can see the point of removing the mechanical resistance of the switch, itself.