Choosing who to save is an illusion? Changing how some characters respond to you is an illusion? Just because your in-game choices don’t lead to 500 different endings, doesn’t mean that your choices in the game are just an “illusion.” The choices offer varying changes to the journey itself, that’s what should matter here.
What exactly was bad about the writing?
You’re entitled to your opinions, of course. But it’s an opinion anyone else really shares. The Walking Dead received universal acclaim, for basically everything that you believe sucked.
What are you talking about?
The choices shape your experience playing the game, that’s what matters. Depending on who you save or kill, your interactions with characters could be very different through playthroughs. Your choices affect how other characters perceive you. I completely disagree that just because the game lacks many endings that the choices “mean nothing.” And this game is the furthest thing from Mass Effect.