Game of Thrones was nearly "destroyed" by pirates illegally streaming HBO content
(www.forevergeek.com)
There were some nerds who pretended to be writers. And those wrote pulp, SF, fantasy, and comics. Those were not real writers.
That just sounds like some hardcore gatekeeping and No True Scotsman bullshit to me.
I also don't think these new series writers are Boomers or Gen Xers, either. They are a bunch of young bloods with shit for brains and a lack of experience. It's not a taught hatred, but inflated egos.
But, you can ruin a sci-fi or fantasy series by hiring the completely wrong type of writer. Those last few seasons of Dr Who certainly proved that, hiring a bunch of fucking soap opera writers, oof.