[GraemeJ]

In the early days, a lot of people experimented with using mouse switches as an alternative to foot pedals (I did myself).  However, one problem frequently appeared - in order to preserve battery life, nearly all mice time out after a relatively short period.  This means, after a period of inactivity, connection is lost and at best, the first time you use a mouse button, nothing happens while the connection is remade.  

This might seem a minor inconvenience when experimenting at home, but it can be a major problem in the middle of a gig.