It's pretty obvious, that while his initial look was problem, there was another problem that you conveniently prefer to ignore. Bruised kid who looks like drug addict hanging from the hooks and smoking cigarettes BECUZ ITZ SO COOL AND EDGY was much more annoying than any hair color they could have come up with.
There was heavily implied story in this trailer, you have to be blind not to see it. And it's tone has little to nothing to with originals, so yeah, when people saw something that looked nothing like DMC and with it's name slapped atop, sure it was annoying.
What the hell did I ignore?! He's a bruised kid because he was chained up and tortured. And that's it! That's all you can get from that trailer - he was tortured when he was younger and now he's fighting demons in the street. Nothing about the dimensional Limbo, nothing about Sparda, Eva, Vergil or any of the other characters that exist in the game, and nothing about the "Mundus is a banker controlling the world through debt, propgandist news, and a spiked energy drink" antagonists. If you're saying you got any of that from a 90 second trailer of Dante being tortured and fighting random demons on the streets, you are a straight-up f#cking liar. Or you can see the future, in which case it makes total sense that you won the lottery and now spend your days sitting on a mountain of cash while spouting bullsh!t on the internet.
Furthermore, implying that it was all done simply for some stupid edgy coolness factor is to specifically dismiss and denigrate what is being seen; "I don't like this, so therefore it is being done for stupid reasons." Sh!t, the same "doing it because it's cool" criticism could have been levied against the classic series when it debuted for appealing to grimdark gothic elements, long coats, and duel pistols that was super popular at the time. The slight difference here is that the concept of torture has actual metric sh!t-ton of value to a story being told, and isn't all just a mash up of really cool sh!t like DMC was (not at all that that is a bad thing, mind you).
And people who said he looked like a drug addict, and ignored the entirely logical conclusion that his appearance was cuts and bruises from all that fighting he loves doing, are a bunch of foolish mouthbreathers. I can't think of any nicer way to put it, because actually paying any sort of attention to it and coming to that conclusion is just plain dumb.
And speaking of ignoring things, you are oddly quiet about how people ignored what the devs were saying and believed completely unfounded rumors about dial-a-combo and overheating guns. That boggled my mind the most when I followed the game, people constantly spouting it off as if it was true, that it was tangible proof that the game would suck, but there was nothing to corroborate the claims, all which were (like so many other rumors) proven entirely false.