I also check in on this comic now and then,usually when I see it on the front page, but from what I could gather, it didn't really seem like Applejack straight up rejected her but was more oblivious about Silverlays feelings or perhaps even in denial (?) Nevertheless, as of now I didn't really get the feeling that AJ rejected her but rather ignored the confession in some way, which is probably the reason why people are angry at her. Maybe she did it out of fear, confusion or just lack of romantic experience, who knows. The comic is not over yet, at least so it seems and therefore I wouldn't jump to conclusions about a characters' stand point, when they aren't even confirmed in the comic yet. Seems like one of those slow-burn romances to me anyway and they are usually always filled with some sort of conflict for the characters to tackle before they finally become lovers.