I think a lot of people here are missing the point of 'sl', 'gti' et al. They're practical jokes, not training aids. Of course you can alias 'sl' to 'ls'! Of course some shells are smart enough to DWIM! 'sl' is there so we can watch the expression on the clewless n00b's face when he inevitably mistypes 'ls'-- probably in a moment of stress.
I had just started using Debian a few days before. I was trying in vain for hours to get a crappy Radeon card's direct rendering to work, futzing around with different settings. Suddenly a train roared across my terminal. "What the fu..." Eventually I figured out what happened and laughed my ass off.
