1. Cis people being in charge makes it seem as though we aren’t capable of being in charge ourselves (or of ourselves), and furthers their own privilege by being able to frame it how they want it, even at the expense of what trans people want. Even the best allies who are fully receptive and take every single thing any trans person ever says to them to heart, never gets offensive, etc is still in a position where, if they wanted, they could EASILY drastically screw over trans people. Now put them in a position of power over how trans stuff is dealt with and presented, and the damage they can do is amplified.
2. These are our lives. If a cis person says something offensive about trans people- it doesn’t effect them. At the most htey say “oh, my bad” and maybe feel guilty and try again later. It effects us, it effects us when people go around thinking offensive things about trans people because someone will use that to hurt us. This is also further amplified because cis people will often listen to another cis person over trans people, so anything busted they say is seen as “more valid” than a trans person saying “that’s busted”.
3. These are our lives. If a cis person wants, they can tune out transphobia, including their own. They don’t have to be aware of it every second, they don’t have to scry to see if an angry comment or dirty look was because they were trans (because they aren’t). We do. Trans people have to eat, sleep, and breathe the reality of being trans, be aware that an offhand remark can change the tone of the night from enjoyable to terrifying, know just how the world sees us (and how we are taught to see ourselves). The reality of being cis does NOTHING to teach you of what it is to be trans, even if being cis while lacking another privilege (eg. being a woman, not straight, person of color, person with disabilities, non-neurotypical, intersex, etc) may help you to understand what it is to lack the privilege of being cis a bit better. But you still don’t know what it is to be trans, and you still have the freedom to spend time not worrying about trans issues, never wondering if someone is looking at you in your new suit because they like how you look or because they think you’re a freak for wearing it, never worrying that someone will make a “tranny” or “sex change” joke and ruin your night.
4. You don’t need a formal club or workshop or anything else to fight transphobia and cissupremacy. As a cis person, you can just speak positively about trans people to other cis people, call out transphobia and cissupremacy when you see it. Reread the last line of point 2- your words are given more power and volume than trans words. Just by saying, whenever someone says “tranny” or makes a “sex change” joke, “Hey- that’s messed up, you’re being a jerk”. Hell, just by not laughing. Just by giving a raised eyebrow and pointed look of “That’s pathetic”, before changing the subject and going on with your day. Vote for trans-positive laws, push your government representatives to be in favor of trans-positive laws. You don’t need a formal club to help trans people. And, quite frankly, it’s better not to have one if you want to be the one to run it.