And I think that's a reasonable opinion to have, since we already have a language (JavaScript) that can do conditionals, loops, and functions much more naturally than some styling system on steroids. And of course you can use any other language to produce the markup in the first place. Do we really need to turn the styling system into yet another Turing-complete scripting language?
I'm waiting for the day when I can forget about both Sass and LESS, and just use vanilla CSS4, CSS5, or whatever comes next. Variables are coming soon. Proper nesting is probably next on the list. I may be wrong here, but I suspect that using LESS (which is closer to vanilla CSS) in the meantime will make it easier for me to transition to CSS4/5 later, because I won't be spoiled by all those fancy features that will probably never get implemented in vanilla CSS4/5.