My wife works for lost luggage on certain bids, and she's a busy girl especially if there is bad weather, maintenance, plane swaps, all kinds of excuses. I'm not checking bags unless I absolutely have to although sometimes i'll check on the return flight for convenience, otherwise, its an IT carryon (Love that luggage) and a backpack that is stuffed with assorted crap and goes under the seat.
Lots of airlines over the recent few years have been more aggressive in contracting out ticket counters, baggage handlers, etc with cheap inexperienced labor, not sure if statistically the numbers have fallen off but it sure seems like it.