Earlier quoted context omitted.
Simple objective reality. Nobody is diagnosing boys as trans or having gender dysphoria simply because they play with Barbies. People in a certain bubble may believe it's happening, but in the real world it takes a lot more than "plays with barbies" to get that diagnosis.
What makes you think you have more access to objective reality than others ?
I know enough people outside of the heteronormative experience to know that nothing about playing with Barbies pushes people toward being trans. It's reminiscent of the classic "violent games make kids violent" line. That's not the case at all -- rather violent kids are attracted more to violent games. The causality is completely incorrect and displays an obvious naivete paired with a pre-existing ideological bias.