>>535340919
Because he works exactly for what you expect. He clears handily every normal event, even EX and S stages, and low ascension IS which is the enormous majority of what the playerbase plays with 100% consistency, so people will keep using him because he works and is very flexible there. High risk CC and IS has a much lower playerbase, while SSS is super easy now and any team clears it and RA has little players. So even though in theory Thorns is bad in most modes, it doesn't really matter in practice. You deploy him and clear your stage or IS run farming mats, that's all he does and all he needs to do.