I hate that ****..
I could be a little biased, having exhaustive experience with classical/conducted music, but I feel like unless you want the '4-clicks and go' effect/sound, there is NO REASON to click in ever..
Everyone should have the tempo in mind, the leader should be able to breathe-as-beat-four and everyone starts.
Maybe a litttttle ambitious for some groups, but to come backdown to earth: it looks stupid to have the drummer click something off and then one non-drummer starts the song. silly
I dep/sub on guitar as well as play bass. I often play the same songs for different band leaders who all want different tempos to the original. One in particular drags the tempo. I ask for a count in because sometimes the desired tempo just doesn't sound right. The count in helps me deliver what the band leader wants.