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It's a well known convention (CTM), it's been part of a lot of front end application shells for years. Like other shells, an HTML boilerplate is somewhat expected to be a delicate, hand-optimised system. When it needs revising (which should be very rare) it should always be reasoned about as a whole. Its job is to bootstrap the front-end environment with maximum efficiency, and that means doing things that would be considered bad programming in another context.