>>213475564 (OP)It's a form of validation, I liked X and it did well, that means thing I like is popular and therefore I am popular, normal, and accepted. If your interests are strange and unrelatable, you end as a capital A Anon saying kek kek based cope seethe based based capeshit kino kek based all day, gaining weight and stinking.
If it's a franchise, it's also an indicator for whether you'll get more of what you like, or less. A poor box office means it is less likely they'll make another iteration, or if they do make one it'll be radically different and wearing the thing you like as a skin suit.