[fvox13]

My job is to create web applications, not to keep track of every little idiosyncrasy in how various browsers have implemented core DOM methods. The jQuery team do a great job at keeping track of that stuff, and ensuring that things are consistent between different browsers. If I need something to be absolutely-blazingly-uncompromisingly fast I can use native methods, but for most people's use-cases, the performance hit you get with the abstraction is not sufficient enough to go back to using flint and steel to start a fire, after we invented the windproof lighter that is jQuery (or $FRAMEWORK).