This subject has been discussed 2-3 times to my recollection. The most recent Blog post was:
"Perfectly legal" doesn't make the activity of rejecting a fellow human being right simply because they are between jobs.
What is perfectly justified is to remember those employers, who operate in this way, and decide if their products or services are essential in your life going forward. And if they can be rejected by you, an individual--your sphere of influence may be interested in knowing why you would make such a decision.