What are you arguing, exactly? Are you suggesting Man of Steel WASN'T a polarizing film at release? Because that's simply just not true. You're also bringing up home video sales when we don't actually know how the new Superman will perform in that regard, so it's sort-of an odd thing to talk about at this point.
Here's what we can basically say happened:
1.) Man of Steel did worse at the domestic box office than Superman, in what was inarguably a better market for both superhero films and just, more broadly, theater releases. If you want to talk about inflation, sure, but then we'd also have to talk about the broad strokes impact that quick VOD / home video releases have on theatrical releases today, and that's a little harder to pin down as outright fact.
2.) Batman v Superman was a relative success, but not the success Warner Bros. had wanted, and the overall reception was extremely negative at the time of release. It was so poorly received, and didn't meet expectations to such an extreme, that Warner Bros. panicked and butchered Suicide Squad in the edit and then went on to leverage Zack's personal tragedy to try to rub out his influence from Justice League. Those aren't the moves of a studio who thinks everything was hunky dory with Batman v Superman's reception, especially given how much worse BvS did relative to the Nolan's Batman films.
3.) Again, if ZSJL was such a huge success, why WOULDN'T they give him an opportunity to follow up, especially in light of Gunn saying Elseworld releases will continue to exist even in the age of the DCU? It's a fact that at least one exec came out to say ZSJL didn't make back the money, but there's actually no evidence to counter that narrative. This is, again, in spite of the quality of the film, which I think is really good.
4.) I can't comment on what you or your acquaintances felt about Superman's marketing campaign, but I can speak to the other points in your second paragraph: Films don't release in a vacuum. Regardless of anything else, Superman is still a DC film, and that franchise / IP is still largely tainted by the stink of the DCEU. We're not coming at this from scratch, even if it is a reboot. It's similar to how Batman Begins performed relative to both The Dark Knight and The Dark Knight Rises, largely because it was coming off of the heels of both Batman & Robin and Catwoman. The film earned positive reviews, and good word-of-mouth, and that resulted in the follow ups doing better. Is that what's going to happen for Superman? I don't know. But almost all of the buzz I hear from people is positive. And again, the domestic box office total is an outright success, it's the foreign box office wherein the film struggled. That's just a fact at this point.