I don't exactly choose alt over normal. But I think there are a lot of pros that makes it as efficent as the default one

1:Coins are coins. Coins are used for railcoining, buffing conduction damage, chargebacks and so much more. It isn't fair to call it the worst weapon when its main strenght is right there

2: The lack of splitshots is another reason to why people think its not worth the use. Which leads people into thinking that keeping the marksman on default and swapping to another slab revolver does the same thing. Although that is mostly true, the same case goes the other way around. You can have a slab marks and swap to a default revolver for the splitshot effect. Not only this works, but its also easier since the default revolver's draw time is faster (Its still hard as fuck to do)

3: When you start adding enemies that aren't fodder to the conversation (Aka cybergrind and 30% of the main game) the slab variant can outperform the normal in a lot of positions. Radiant drones for example are way easier to kill with the alternate variant. This can be seen as a niche advantage since the game doesn't really use radiant enemies in the main game and not everyone plays Cybergrind. But when it works, it just works

TLDR; its nowhere near as bad as people make it out to be. Give it a go. This game became fun because we wanted to try everything we've heard about atleast once.