Sorry if this is a stupid question and the name for modern Goths was just chosen because it sounded cool.
Not a stupid question! But you may be interested in my answer to When people in the Roman Empire ca. 410 AD say the word "Goth", they were thinking of barbarous tribes that came from their northern border. Now, when people say the word "Goth", we think of ruinous castles, gloomy churchyards, and teenagers with heavy eyeliners. How do these two meanings relate?