however is an indication of how something should be understood. "Strong" could (and often does) mean "bold" in a browser, but it could also mean a lower tone for a speaking program like Jaws (for blind people). And strong on a Palm Pilot may be an underline (since you can't bold a bold).
HTML was never meant to be about styles. Do some searches for "Tim Berners-Lee" and "the semantic web". is semantic - it describes the text it surrounds ("this text should be stronger than the rest of the text you've displayed") as opposed to describing how the text it surrounds should be displayed ("this text should be bold").