Why do you consider it a good thing to not use standard controls?

The operative piece of the above post (to me) is "working _against_ the browser", not the existence of custom code per se. IME lots of problems with UI development have come (partly) from shoehorning tech to do something it's not meant to do, at the expense of speed, accessibility, and general usability. If the built-in thing doesn't do what you need, by all means build something that does, but it's worth keeping in mind that often the useful thing that end users actually need/want is the built-in thing.