Even in Deep Red/Caïssa builds, Bishop doesn't see much love. There's a lot to dislike about Bishop, not the least of which is that one of only four Caïssa programs is wasted here. Sorry, chess decks.

Unlike Rook, Bishop targets one piece of ICE rather than a whole server. Unlike Knight, Bishop provides no utility for making runs on its own. Unlike Pawn, Bishop offers no utility for accelerating the pressure you're ideally putting on the Corp. (This may be the only time someone has complained about the cheapness of a program, but Bishop's 0 cost doesn't even synergize well with Pawn!)

I suppose Bishop could be used to increase the utility of Mimic and Yog.0, but that would require you to either know in advance which cards need targeting or blindly facecheck ICE until you find the one that needs weakening. At that point, you've probably lost the damn thing to the damage you took anyway. And God help you if you need to move the Bishop to another piece of ICE on a central, because its convoluted movement rules make it all but worthless if you're focusing on either centrals or remotes.

The ideal situation for Bishop is to be able to Yog something like a Tollbooth, but for your money, why not just use a more general-purpose Datasucker or Parasite? Just pack a MemStrips and save the Deep Red memory for Rooks and Knights.