1. Stop assuming I am stupid.

2. I know code reuse technics in css, they are mentioned in the presentation. Cascades do not work for component based development. Adding multiple classes to an element leads to awkward code and also will lead to namespace conflicts if you don't name everything very specifically.

3. Vendor prefixes are there and will be used for new features too. They will not go away. Precompilers can't avoid generating all prefixed variants.