User blog comment:RoznosicielCiast/Why Sejuani is getting reworked?/@comment-128.230.241.31-20130215011007

Its because everything she did, someone else did better. On top of that, she is widely considered to be a very boring and unpopular champion. Sejuani sucks something fierce until you pour a significant amount of cash into items for her. She can't really tank with no tanking steroid, she doesn't really do much damage unless her W is up on a frosted target, which, by the way, is a pain in the ass to apply, and extremely underwhelming.

tl;dr: She's not fun for the vast majority of the player base, and is mechanically shitty.