I completely agree with you. That said, you can restrict your usage of these things. On the project I'm currently working on, we're only using three features:
1. constants (mostly for colors and a few sizes)
2. mixins/functions/macros for not-completely-standard properties (e.g. gradients, shadows), makes it easier to not forget a prefixed version, easier to update the definition when needed and much, much easier to read
3. nesting and continuations, especially for styling various states of e.g. a link (having to copy/paste a given selector 4 times and change the pseudo-class is no fun).
Still requires some care though, overusing e.g. nesting can mean you find yourself with fucked up huge selectors in the final file.
1. constants (mostly for colors and a few sizes)
2. mixins/functions/macros for not-completely-standard properties (e.g. gradients, shadows), makes it easier to not forget a prefixed version, easier to update the definition when needed and much, much easier to read
3. nesting and continuations, especially for styling various states of e.g. a link (having to copy/paste a given selector 4 times and change the pseudo-class is no fun).
Still requires some care though, overusing e.g. nesting can mean you find yourself with fucked up huge selectors in the final file.