You are talking about large long term existing companies. I am talking about a new technology where (with a few notable exceptions) there are few employees, a high proportion of those employees being technical people and generally companies with little spare cash that are trying to make something from nothing.

That is very hard work and phones are expensive to man. With the best intentions in the world technical people make crap phone operators. They can email sensibly with the needed information but they cannot generally man phones and talk to planks about why the printers don't work when they are not plugged in.

That is why, for the sake of the industry newer forms of communication should be embraced, endured and accepted.