He has one of the most unique designs in the show, great voice acting, subtle character development, a character dynamic with one of the mane cast that develops over seasons, involved/a big part in some of the most fan-favorite episodes such as Where and Back Again, Twilight’s Kingdom, The Return of Harmony. In yet some treat him like he is a ojectively trash character after his reformation. Also apparently discord causing trouble makes him a bad character for plenty….even though HE IS A SPIRIT OF FREAKING CHAOS and hasn’t had companionship for his entire life so ofc he struggles with learning friendship and being better.