I care because I know developers have worked their ass on a game and will wait and see the reception their game get.
Ofcourse I hope for the best for the game franchises and developers I am a fan of. Despite not playing the game myself: You hope the general consensus for the reviewers is that the game is good/great/a masterpiece. (Usually I agree with reviews too so thats another reason). And if you're hyped for a game: There is nearly nothing more exciting than hearing good about it (Aside from actually playing it XD)