The theme of the game is its soul; the mechanics are its body.
A fitting theme is not only important for player immersion, but also helps in teaching the game, as it is much easier to learn a game when the theme and mechanisms match.
I like the game mechanisms. I’m delighted to try games with interesting new ideas, even if the games are not well developed. I’d appreciate it if the publishing houses allowed themselves more time with their games. Games need time in development. With computer games a large effort is made, with board games sometimes only the most essential is done.
I’m not smart enough to design mechanisms in the abstract. I’ll leave that to Reiner Knizia and the mathematicians. I try to tell a story about something (usually historical and political, in my case), so I work on mechanisms that fit the story.