I understand your point, but subtitles appeared on title screens very often that didn't make them part of the title. On the game 1869, the title screen for the AGA version just says 1869, while the ECS version says 1869 History Experience Part I. If taken literally, that would be completely incorrect to title these two games as such in a database. The title screen for Last Duel says Last Duel Inter Planet War 2012, but clearly this is not the title of the game. Other examples: Search for the King's title page calls it Les Manley in Search For The King. Watchtower says Watchtower War Has Never Been As Deadly, Malta Storm says Malta Storm Version 1.33 The Axis Siege of Malta December 1941 to September 1942 (try fitting that one into a TOSEC filename!), and in a more similar example to the Manchester United debate, F1 (1993/Domark) also includes on its title page An official product of the FIA Formula One Championship! There's many more examples, but I think this defends my point.
Another point to remember is that the person who makes the title screen is not usually the programmer, which is why there is often discrepancies betweens titles and spelling from box to title screen to actual game.