Probably a more practical use for coffee shops, stores et....Since you need a boarding pass to get passed security I don't see theft rings opperating inside airport terminals as the most efficient space for this sort of scam.
The reality is a decoy isn't all that necessary most of the time. I can't tell you how often I see women leave their purse in the shopping cart at the grocery store while looking produce or meat over in the counter. I once had a coupon clutch (looked like something a woman would keep money/checkbook in) snatched right out of my shopping cart while looking at hambruger in the meat counter. It took the theif all of a minute to steal all my expired coupons and a couple that I could have actually used. They were probably disappointed at their haul but it proved to me there are some pretty brave individuals that will take a risk to grab what they believe is valuable.
As for waiting on my bag. I buy UGLY inexpensive luggage and sit back, relax and wait. The brighter and uglier the better. My current favorite is a bright yellow bag with a huge Felix the Cat on one side. You'd like the think everyone would realize that's not their bag. Instead there's at least one moron who checkes the name tag as it goes around, then grabs their standard black bag off the belt. Maybe they just want to see what idiot would buy such a hideous looking piece of luggage?