“even less social stigma”
The problem is not that there is less social stigma—it is that are positive incentives for claiming to be a lesbian or bisexual.
It helps with college admissions.
It helps with obtaining jobs, particularly in certain sectors.
It help with political careers in big cities.
This is about incentives—people will take advantage of the “system” any way that can.
You’re right. It helps to be part of a victim group. Subsidize or incentivize an activity, and you’ll get more of it. I read somewhere that American Indian populations are growing faster than birth statistics indicate. Why? Because other races are claiming to be Indian to access benefits for minorities.