if youre fighting a boss where stuns landing is important, the dps increase of leg sweep is not worth the higher chance of wiping. its selfish to increase your DPS at the cost of a raid-mate's life

also macros generally round time up, so as opposed to having a 2.4s GCD you have a ~3s when using macros (from what another thread said). taking off all my gear and doing TTT normally ended up substantially higher than TTT macroed. (about 12% higher in both DPS and hits)