To write a novel is to embark on a quest that is very romantic. People have visions, and the next step is to execute them. That's a very romantic project. Like Edvard Munch's strange dreamlike canvases where people are stylized, like 'The Scream. ' Munch must have had that vision in a dream, he never saw it.
I think that veganism is a totally great choice with incredible benefits, but I don't think it's reasonable to expect other people to be vegan or to expect everybody to be vegan. You can proselytize all you want, but being vegan is a pretty intense choice for a lot of people. You can encourage people to eat vegan more, certainly, and I personally eat vegan quite often.