[TexanFeller]

Those people should not have been hired, or should have been let go at 6 months when that became obvious. The real solution to this problem doesn't fit with most management methodology though.

[SonOfKyuss]

It only makes sense to fire someone who needs to be nudged into getting their job done if you can find a replacement at a similar cost who doesn’t.

[jwHollister]

1+1 is often less than 1.

The mediocre unmotivated person is dragging down the other, killing their motivation. You'd be better off without them even if you couldn't replace them.