I can't see how it creates good viewing.
To send a keeper off in a penalty shoot out is basically handing a victory to the opponents. Unlike in normal time, assuming a slot is still available, if you have a keeper sent off you can sub off a player for the reserve keeper. But in a shootout, you can't.
They're getting a retake anyway, so he hasn't actually achieved anything.
Plus keepers are the only players left that can still get cautioned/sent off in a penalty shoot out in a match situation. Outfielders will only receive their marching orders if they're saying or doing stupid things on the half way line (violent conduct or foul language).
Can understand the caution etc in a match but in a shoot out, nah. Don't agree with it.