Retaliation is hardly the only reason for publicly bringing up sexual harassment (or, in the case of someone like Kavanaugh, unrepentant sexual assault), but the safety of others is another huge one. Whether someone is just a creep or is possibly an actual danger, people deserve to know so they can protect themselves. Especially when court systems so often fail to protect victims, actively engage in victim-blaming, allow evidence to expire, and let perpetrators run free.
In regards to the chuggaaconroy situation, personal safety is another concern when it comes to addressing situations like this. I'm not saying he's like this specifically, I don't know him (and don't particularly want to after seeing his behavior), but oftentimes the same people who engage in unsolicited sexual messages and persistent follow-ups when ignored are the type who don't react kindly to rejection or criticism.
For women and LGBTQ+ people especially, even just saying "please stop, you're making me uncomfortable" can get people physically hurt or worse. Sometimes bringing these matters to light is the safest way to handle it, and after someone has already engaged in harassing behavior, I don't blame anyone for not feeling comfortable trying to have a constructive conversation about boundaries with them.
I don't know her either and can't speak to her character, but I feel like the framing of Lady Emily as "trying to ruin someone's life" is unnecessarily demonizing. At the very least, chuggaaconroy made a very bad series of mistakes and hurt a friend. It's not her fault he sexually harassed her and I see no reason why she should be obligated to stay silent about it to protect him and his reputation. Coming forward about stuff like this isn't fun or easy either, it's a very scary thing. Even if you think it could've been handled better, I think she and others in her position are deserving of empathy.
Now I'm craving some brontosaurus ribs... 
