In the eyes of many travelers, the recent announcement that Spirit Airlines would start charging passengers an additional fee for carry-on luggage, simply crossed the line.

The only thing worse would be the plan currently under consideration by Ireland-based Ryanair to remove some airplane lavatories to make room for six more seats and then charge passengers one euro or one British pound to use the only bathroom left onboard. The one-lavatory planes would only be used on flights of an hour or less, but still…

It certainly is not news that airline travel isn’t what it used to be. Despite the fact that air travel numbers continue to decline, airlines seem completely oblivious to the comfort and care of their passengers.

Much of the blame is placed on the rising cost of jet fuel, but a top Spirit official said the impetus for the new carry-on luggage fee wasn’t weight; it was the extra time it takes for people to stow all that luggage in overhead bins (what will fit under the seat is free) — a problem that obviously increased after airlines started charging for checked luggage. The point, apparently, is now to encourage people to check luggage by making it even more expensive to carry it on.

Neither the Florida-based Spirit nor the Ireland-based Ryanair fly to Kansas City, but service-reducing and revenue-raising measures often begin in small regional airlines and trickle up to major carriers. Southwest Airlines, with its highly touted “bags fly free” campaign is the only remaining major U.S. airline that doesn’t charge for bags.

Americans like low airfares, but when a $150 round-trip ticket turns into $180, $200 or more when you check a bag, the airlines are fooling no one. In most cases, passengers would rather have the cost of taking a modest amount of luggage included in the price of their ticket.

These extra fees might eventually spur a new parallel business for some crafty entrepreneur. Many travelers already choose to ship bags or boxes to their destination or home. It can be less expensive than paying baggage fees, but arrival times aren’t precise. What if UPS or some other express shipper could figure out a way to pick up bags at an airport or your home and have them waiting at your hotel when you arrived at your destination? Given airline baggage charges and the possibility of bags being lost or mishandled, it could catch on.

Spirit’s carry-on fee has gotten the attention of several U.S. senators, who are not amused and are looking at legislative moves to prevent the implementation of the fee. Federal legislation on the matter may be an overreaction, but it’s an indication of how frustrated lawmakers and their constituents are about add-on fees.

Airlines seem to be mystified by the continuing decline in air travel. Rather than reducing seat size and charging for everything from snacks to a trip to the toilet, perhaps they should consider providing passengers some service for which they might be glad to pay a few extra dollars.