The bigotry is on the same level, but I think JK Rowling is actively militant on a far different level compared to Orson Scott Card. Just looking at their twitter for example, OSC tweets maybe once a month and 9/10 times it’s about a book signing or other such promotion. JK Rowling’s feed is a constant flow of hatred on trans people. She tries very hard to make sure you are reminded of her bigotry every single time you hear anything about her.
The reach is different too. OSC has some 16k followers. Rowling has 15 million. It’s natural for her to attract a much higher degree of disdain.