Noone is against OpenAPI, definitely on the author, thing is that OpenAPI is just not for everything and AsyncAPI complements the rest. AsyncAPI doesn't have to

Noone is against OpenAPI, definitely on the author, thing is that OpenAPI is just not for everything and AsyncAPI complements the rest. AsyncAPI doesn't have to imagine anything, ecosystem is already there :) MQTT,Kafka, Websocket and others were there long time before AsyncAPI. I recommend you look at the article once again.