What exactly are we talking about when you say "besmirch"?
This isn't a court of law, we aren't by and large talking about legal proceedings, reasonable doubt need not apply. Even there there really is no such thing as "confirmed", not in an absolute sense.
On an individual level we besmirch people all the time, every time we gossip and whisper, every time we voice suspicions in private or public, every time we speak badly of someone we just dislike, it's normal human behaviour but we've never really seen it in this context and to this level. We are talking here though about broader conversations which are happening across society, conversations where women's views are finally being heard, their experiences finally being shared. Those experiences and the views which come from them are ugly, far uglier than most of us would like to have imagined.
Society has allowed men to be bullying, misogynistic, violent and controlling, it has turned a blind eye at every level, the family, the workplace, religion, the legal systems, the political structures. Every power base has without exception been dominated by men and structures which enable us (yes I'm male, and straight), shaping society to favour us at every turn, turning a blind eye, enabling and even sanctioning abuse throughout history.
What we are seeing now is a shift in that power balance, a shift away from a place where women were silent victims. Absolutely the odd decent man will suffer as a consequence and that is truly terrible on a personal level, but on any pragmatic reading of ethics the greater harm is being reduced and restricted. Under reporting of sexual offences (which themselves are only the tip of the iceberg when considered against the backdrop of "legal" but still misogynistic behaviour openly accepted by society) has long been and remains a far greater problem, to focus so adamantly now on such a small number of injustices as an ethical stance is a fairly uncertain proposition unless you were already making far louder noises against the greater evil.