I don't quite understand the logic where people being laid off from their positions / responsibilities and the jobs being posted are similar in nature.

For one, are you really saving costs when you're losing some individuals with deep knowledge of the job for which you would need to re-train a new individual to come up to the same speed and productivity as with the previous person doing the job?

Doesn't this also make productive / talented / hardworking people shy away from your job posting when they know that your company recently laid off employees?