Because after shit pay being the desk girl at Walmart Tire Center for 2yr you can easily convert that into a service writer job <fast forward 40yr> and then retire from your job as regional support manager for <company that makes industrial doodad>
Compare with thotting around on the internet where you can make a ton of money up front but you're basically racing the clock because your body won't be nearly as lucrative of an income at 30 and you'll be starting from square one-ish. Can you potentially take the cash and pivot into a career that will carry you to retirement? Sure, but it takes a work ethic and level of discipline that is uncommon.
It's like the female equivalent of being a marine rifleman for several enlistments. You get out at ~30 with few marketable skills, hopefully a good work ethic and a high liklihood of f-ed up knees.