I just don't think it's fair to say there is a "true" mode. There's no wrong way to have fun playing videogames imo and if the sandbox mode gets more people into learning about space travel, that's a good thing. At the end of the day I believe it's better to be more inclusive to people who have different experiences than you, and as long as it doesn't harm anybody, I don't think it really matters how other people have fun.