Considering the limited available audience for the evening daypart, KISQ/CCM+E are probably cutting their losses and putting more effort into the dayparts that advertisers really want.
"Night Grooves" was probably valuable only because it gave Kiss something to talk about during those dayparts that matter. If a show is not generating real revenue, it isn't worth a lot of effort to Clear Channel and similar companies. If you were a fan of the show and not an advertiser, you're probably SOL.