The Kindergarten-Out: Because Milady has nothing else better to do.

[Elin]

I dunno, I mean that particular bit there happens to be something of a set up for a bit of a dark punchline.

And some expressive humour.

Walt's reaction to Jesse's plan to dissolve the first corpse was rather hilarious. As was Jesse's eventual reaction to why that was such a terrible idea.

Yeah, I know. I just remembered it taking a little longer to get into the really brutal stuff, rather than acid in the bathtub from the off. Then again, I suppose the pilot has Walt suffocating two people with phosphine gas.

The first series is sort of darkly comic because Walt and Jesse... so aren't the hardened criminals they're trying to be. By the later series, the things they've done have turned Jesse into a bit of a wreck and Walt into... well... Satan. Not so funny anymore.