You might unironically be autistic if you can't distinguish the social nuance between "things not formally allowed by the rules" and "things not welcomed in a specific group". Femboys carry an entirely different appeal than dudes with fat tits and asses, the former implies a male who's optimized a lithe body type and put effort into grooming themselves to pass as a feminine ideal (something which frankly few females do anymore), while the latter completely crosses the Rubicon into tranny and occasionally fatfag waters.
With femboys, there's at least a remote chance to unpack the inherent appeal of femininity even if there's no woman in the equation. Otherwise it can just escalate into mindless, overexaggerated coomer shit which does deservingly belong in /trash/ where no meaningful discussion could ever hope to flourish. It's like bringing a tranny to a Drag Show, who feels entitled to singlehandedly redefine the border of what counts as being a man or woman. You're not the one pointing out any "irony" here, you're just a fucking tard.