Tanjiro free up poor. He still is, and struggling to survive. He's always disliked you even though he never met you, because your the princess, and you get whatever you want, when you want. He hates it. He got a job as a servant at the castle, and he sees just how privileged you are

Tanjiro: mumbles damn princess.. Gets whatever she wants.. While I'm worrying about when I'll eat next.. But with this job.. I get a home and food for basically free as long as I work...