Why did they change Bolts of the Dead (revived rogue) to Wails of the Dead?

[thoroughlyS]

I like to keep up with Unearthed Arcana, and when I first saw the revived archetype (eventually renamed to the phantom), I thought Bolts of the Dead was a pretty cool feature, which moved Sneak Attack from the Attack action to the bonus actions of Cunning Action. I don't really see a problem with this design, as I don't think this would meaningfully change the round-by-round for the average rogue. Can someone enlighten me as to why this concept had to go? Is there something obvious I'm missing here?

[DracoKnight]

It allowed you to take the Ready action with your main action to set up Sneak Attack on your reaction, while still getting Sneak Attack on your turn with your Bonus Action.

Normally Rogues want to get Sneak Attack on their reaction anyways, as well as on their turn, but this made it too easy. So it got changed.

[thoroughlyS]

Ah, that makes sense.