They literally have to. Midway has one of the shortest runways in the country, so they have to hold the brake and go max throttle to get airborne in the limited space. Same reason the landings are usually "firm". Most pilots love it lol
Done that one many times, love my Airport, Love SWA at MDW . . . love the nonstops to LGB! Where I once worked as CSA for WinAir, Allegient and jetBlue!! Miss my beloved California . . .