Several companies pledged to oppose it. Disney initially took a noncommittal position, then over-compensated (to make up for their perceived inactivity) by saying stuff like how they were going to actively lobby against the bill (and I seem to recall those who voted to pass it?). That, coupled with the leaks, made them more of a target than others which took a more public position in opposition to the bill early on. I also believe Disney’s outsized position in entertainment (and family entertainment in general) made their actions more noticeable.