If lots of people start using a semicolon to connect words because they think it looks cool, then eventually it will become standard usage in World English and no one will complain
No need to speculate on "World English"; the series is Japanese, from a country simultaneously using four different official alphabets, and numerous languages in daily life. Japanese publishers feel, and have felt very comfortable disregarding usual English grammar rules in their naming conventions. Note, even in Japanese, without translation, the series is still named "Steins;Gate". This disregard of usual English usage in titles has been true for many years now in Anime and Manga. It may be amusing to imagine the future response of "Users of Standard English", but totally unnecessary. For many years now, knowing native English speakers have shrugged, saying "It's from Japan!"