Its JC Staff, of course shes going to get the lead. Shes the lead in almost every Dengeki light novel/manga adaption they do, either as tsundere voice or her playing a male
I don't get peoples beef, yeah SNS and ZnT fell a bit off course (ZnT 3 seems to be sticking way closer to the novel though, s2 was meh), but I think they can do a series justice if they get enough episodes, sometimes they don't have a choice but to change the story a bit or it would just be awkward - for instance