BALTIMORE, MARYLAND - OCTOBER 11: A Southwest Airlines airplane taxies from a gate at Baltimore ... [+] Washington International Thurgood Marshall Airport on October 11, 2021 in Baltimore, Maryland. Southwest Airlines is working to catch up on a backlog after canceling hundreds of flights over the weekend, blaming air traffic control issues and weather. (Photo by Kevin Dietsch/Getty Images)Getty ImagesHaving a distinct differentiator for your business is critically important. For many years, the biggest differentiator for Southwest Airlines has been free checked bags.Loyal fans have posted on social media about the perk, even blasting other airlines for their constantly evolving bag policies and seating fees.I can relate to that: On a recent trip, I found that even my carry-on was slightly too big and had to be checked as paid baggage.Ive known about the Southwest perks for a long time, including the one where you can pick any seat without an upcharge. (Sadly, that ended in January.)Southwest recently announced the free baggage perk was going the way of the dodo bird -- that is, it will be extinct. Instead, there will be a fee attached -- although the airline didnt actually announce what the charges will be. Anyone booking flights on or after May 28 would be charged for bags.Predictably, social media followers went a little ballistic.Southwest, you lied to us, said one poster. Another suggested the new CEO tanked the company. A tweet claiming the COO of Southwest said we need more revenue to cover the costs seemed a little unbelievable until I looked it up on CNBC.How Southwest Airlines is stirring their own potIn case you havent followed the airline industry and all the changes weve seen over the last few years, this is just one more example of how the industry is in trouble.People are fighting on planes, camping in the wrong seats, and disrupting air travel. Airlines keep nickel-and-diming us to death with extra charges.Meanwhile, Southwest has retained a high degree of loyalty. They even used the slogan two bags fly free for many years as a way to draw in new customers and differentiate themselves from all of the airbus drama.Theres a lesson here for all of us. As I mentioned, differentiators are good. At my local cafe, theres a booth at the front of the store thats meant for people to ask questions, find out about the Wi-Fi password, and just check in with the owners. It makes the experience feel less sterile. Customers like to feel like theyre getting extra service.The change at Southwest is causing an uproar with social media followers mainly because it seems so abrupt -- this was always a differentiator and now it isnt.The whole saga reminds me of when Netflix decided that some movies and shows were not available unless you upgrade to the ad-free subscription plan. Netflix was always a one-fee shop. When theres a gotcha like that, the masses revolt.How this will all land with Southwest AirlinesSouthwest has a bit of a problem on its hands now.Judging from the posts Ive seen on X (and they keep pouring in as I write this), even diehard Southwest fans are upset.I suspect they will reverse the decision. What was once a perk of flying Southwest Airlines has now turned them into just another revenue-obsessed company.