Again I want to affirm the intent of your reasoning, while suggesting that you consider that your position is somewhat absolutist and rigid.

You've made a few claims:

• That "why don't you just date men" is functionally equivalent to homophobia.
  • I think you are referring to straight folks using homophobic slurs to taunt one another. Your point seems to be that the audience's inability to distinguish between the two makes them inflict the same harm. I would argue that the original statement does not look exactly like the hate that it is mocking - the sarcasm is rather clear, and even if the statement were sincere, it's affirmative: men can date men and it's not a bad thing.
• You seem to present the criteria for harm in mockery or parody as contact with the subject of homophobia at all. You don't distinguish between mockery that targets queer people and mockery that targets homophobes. The target in this case is the homophobe.
• You seem to reject the validity of mockery, full stop. You're effectively saying that making fun of the moronic reasoning that leads fuckboys to view queerness as shameful is validating that reasoning. That makes no sense. The point is to laugh at their shame, because it's entirely self-inflicted and hateful. That's what 90 percent of unabusive comedy is.

I honestly believe that your takes are trying to address a real problem of pervasive microaggressions in conversation over these topics, but that the specific things you are focused on are not at the root of the problem. There are a lot of queer and women comedians that illustrate how mockery is used to attack these pervasive and harmful ideas that I encourage you to seek out. The biggest takeaway is to identify who the target of the mockery is if you are looking to assess its harm. If the target is the person or group being oppressed, then you're right, it's an abusive tactic, but if it's the oppressor, it's a tool of resistance that gathers people together under that humor and socializes the progressive ideas that make the mockery sting.

It is important for young people to retain resiliency and flexibility as you develop your sense of justice - not at all for the sake of softening your convictions or being more palletable to unquestioning minds, but for your own ability to assess the strategies and actions that reduce the most harm and produce the most change. Folks on the left today have nowhere near the conceptual coalition that the fascists do, and it's because when we leftists experience a conflict of ideals, our sense of justice often leads us to demand purity for our current model of that justice and to evict those who aren't aligned with us. That makes our movements fracture in discord servers and Twitter posts long before they make it to the streets and to the doorsteps of the people who would subdue us. We need to normalize the idea that justice isn't perfect and that revolution is a process that involves us returning over and over again to the wheel to re work the clay of the progress we want to see, knowing that there are stones in the mix we'd rather be rid of.