Here are some guidelines for Civilised discourse online, courtesy of Discourse.
- Don't be a Dick: Don't be creepy; use common courtesy and respect others. (Behave yourself with dignity; this is a good place.)
- Improve the Discussion: If you aren't sure your post or comment contributes value to the discussion, don't submit it.
- Be Agreeable, Even When You Disagree: Criticise ideas, not people. Provide reasoned counter-arguments that improve the conversation. Please avoid name-calling, ad hominem (personal) attacks, tone-vs-content responses and/or knee-jerk reactions/contradictions.
- Always Be Civil: Don't carpet-bomb people's inboxes with copy-pasted gibberish or harassment. Respect boundaries. If a person's profile states "no cold messaging unless XYZ" (or similar), respect those rules if you do send a message. Nobody owes you anything, not even a response. Don’t post anything obscene or sexually explicit if unsolicited.
- Don't be a Troll: Do not post/send hate speech or anything that a reasonable person would consider offensive or bigoted. If you do ruffle feathers, offer a sincere apology if required.
- Keep it Tidy: Use good spelling and grammar. There are tools you can use to help you with this. If you're not writing in your first language, please make that clear.
- No Catfish: Don't pretend to be someone you're not or misrepresent yourself. (Keep your profile up to date and root out inconsistencies; people will notice them.)
There's nothing particularly difficult to adhere to there, it would seem to me. However, judging by what I have seen of the content that women post regarding what reaches their inboxes/DMs online (merely the tips of the shitebergs men sail to them en masse on a daily basis), it seems that a lot of people either don't know these seven simple rules or have forgot to adhere to them.

The above image (a composite of ads I encountered while visiting PTC ad pages when milking crypto faucets) is how I think dudebros see social media (particularly Fetish) sites. It would certainly go a long way to explaining (but not excusing) their behaviour online.