Probably because they're at a job so crappy that their employer forces them to use IE7.

"Screw you nerds, i'm going to change bedpans for the elderly"

From what I understand, there's a reasonably large market for temporary nurses, for times when a hospital is understaffed. I suspect it's acceptable to look for a new gig before your current one ends.

Edit: It also looks like hospitals, not nurses, are the actual customers.

One might ask how those job offers end up on the site. Other unemployed nurses, or hospitals?

People even use their current work emails for job applications.

Someone should probably tell them not to do that.

Maybe they don't have computers at home.