There's this rising narrative going around that if you ask specifically for a CIS partner, you're a transphobe. That could be true for some people but it's not fundamentally related to bigotry. Moreover, this narrative, the "if you only want a CIS mate then that is prejudice" is trampling on one of the most important rights a person can have: the right to choose who they want to get intimate with.
First of all, transmen are in fact men and transwomen are in fact women. Let's get that out of the way. This isn't a foot in the door for "trans this really isn't that" narratives. What this is about it is the freedom to choose who you want to be intimate with. That right is sancrosanct, it is absolutely inviolable.
And yes, there's plenty of issues that make transgender dating a special issue. If someone reveals their TG status they can be open to hate crimes and even deadly violence. However all marginalized groups are special in their own way. As a black man I don't think it's racist if a woman says she doesn't want to date a black man. I face oppression, too. My class is special in its own way. One group isn't more special than the other. None of us have the right to force ourselves upon those who don't want to be intimate with us, even by omitting who we really are.
Really, if you have to deceive or hide who you are in order to date someone, do you really want to date them? I wouldn't. That's not fair to you and you're denying them their right to choose who they want. What do you think will happen when the person wants a CIS mate and they discover the truth? They're going to get pissed and dump you. Now you have to shame them into staying with you: "If you loved me for real this wouldn't bother you"... that's not going to convince anyone. They're either going to leave, or they'll resent you forever. That's just how it is. You can be mad at that but that's about as effective as protesting the rising of the sun. There's just no way to win once you've gone down that road.
"I want a CIS mate" is not the same as "trans women are not women" - one is a preference, the other is harmful prejudice. On the flip side CIS people who do date trans people shouldn't be shamed for their choices either. A man should be free to date a trans woman and not catch flak about it. Trans people should be able to be openly trans and not face hate speech or threats to their well-being. This, without any exception whatsoever.
The fundamental fact is when you shame or worse abrogate people's right to choose who they want to get intimate with, it's not going to end well for you. All you're going to get is people who resent being coerced or bullied to date people they don't want to. And that's not something the country, or the world, will ever put up with. Except that right now, most people don't imagine they can be labeled a transphobe just for wanting a CIS mate. And unpopular opinion: that should be nipped in the bud.
You should, of course, have your preferences, and your deal-breakers, and whatever else. So if you find someone you are interested in is trans, and that's a deal-breaker for you, that's fine.
But there is a difference between that and putting in your bio "No Trans People." Is being trans your only deal-breaker? What makes that a deal-breaker worth calling out, but not others? Before you put "No Trans" in your profile, I would ask you to consider that, if you are an athletic person and want an athletic person, would "No fat women" be something you would feel comfortable putting in your bio (even if that was a deal-breaker for you)? What would you think of someone who puts "No black people" in their bio?
If they have any sense, they will let you know either in their profile, in conversation before-hand, or during the first date or so (before things get intimate), and you can politely end things, just like if you found out they were Scientologists or several levels up in an MLM (or both). Hell, it may take until a third date, like finding out they don't just like, but can relate to Olivia Rodrigo's music. (In fairness, those three were objectively bad, but I don't know any of your non-trans related preferences, so I had to go with some things most people should consider deal-breakers).
The point is, people look for and look out for a lot of things, but I only ever hear people complain about it being rude to put "No trans." It kind of makes it clear that the person saying it has a particular issue beyond just dating preferences.
Tact does matter. That is why I say "seeking cis man/woman" is better than "no trans man/woman". "No black people" is bad, "prefer SWM/SWF" is better and acceptable IMO (disclaimer: I'm black), "looking for athletic man/woman" is better than "no fat people", etc., just my opinion.
I take your point, and agree. The positive (as opposed to the "No xxxx") seems generally to be more polite.