I don't think anyone here, well other than
Tobias, thinks or believes that Superman is going to stay dead.
As mentioned before, the issue that people (like myself) have with pulling the "death" cliche on Superman is the timing of it all.
Superman's only been in one film prior to this one and the DCEU is getting prepped where it can finally unveil the Justice League to fans and audiences alike.
Not only would the "Death" arc/route have minimal meeting if done now, but it would end BvS on a downer note while severely limiting his screen time and interaction with characters in the first ever Justice League film.
When Thor was stranded in Asgard at the end of his first solo film, they completely went around explaining the full details of how he came back to Earth, which allowed him to have some time in developing relationships with the other members. However, he was still limited to how much time he could spend with the other members.
I seriously doubt that if Superman is killed in BvS, that they would gloss over the details of how he comes back alive as quickly as they did with Thor's return, thus making Superman an literal one act character in "Justice League".
At this point, I think the only people that are okay with this are the ones that are bigger fans of Batman, who already know that the proverbial keys to the kingdom await for their character.