1. Game system is always less important than who you play with.
2. Dungeons & Dragons is the most widely-played RPG.
3. Anyone who likes any edition of D&D should be able to understand all they need to know to play Lamentations of the Flame Princess (or any other retroclone or old-school game) in minutes and will be within a stone's throw of a premise and theme that they've already signed on to.
4. Due to the art and marketing, LotFP offends more boring people than any other game.
5. LotFP offends no interesting people.
6. Therefore if you sit down to a table with people who've agreed to play LotFP, you have screened out a larger percentage of boring people than you have by choosing any other game while still drawing players from a diverse pool due to the bar for entry--mechanically and thematically--being extremely low.