Southwest flies 737s, which hold around 100 people (says Wikipedia). I can't imagine getting 100 people off a plane and then another 100 back on, plus stowing/unstowing baggage, all in 10 minutes.
Maybe that's why Southwest offers free checked baggage, to reduce the time passengers spend handling carryons.
And that was the original model and configuration which was released, since then we have seen variations of model and configuration with up to 215 seats on a 737 according to wikipedia.
Southwest flies 737s, which hold around 100 people (says Wikipedia). I can't imagine getting 100 people off a plane and then another 100 back on, plus stowing/unstowing baggage, all in 10 minutes.
Maybe that's why Southwest offers free checked baggage, to reduce the time passengers spend handling carryons.