[Zababa]

If writing code for your abstraction isn't faster and the resulting code isn't faster, then surely not using it is useful sometimes? "better visibility of platform dependencies, easier security audit, portablity, ease of refactoring/deprecation of platform APIs" don't really matter that much for web browsers if you're not using the latest new shiny things, the backbone of the web is really stable.

[nsonha]

I guess to me the reason is that I want to deconstruct problems properly and focusing on thinking inside the domain of the problem. It helps me think by pushing all the platform junk out to the edge.