I like the WW2 story as well, but when chat increases total interactions and conversions, it’s hard to make a case for survivorship bias.
For example, chat popups that ask you to interact before you've had a chance to even read the title of the page.
Every customer who hasn't purchased yet is part of a funnel, and you absolutely CAN test with an A/B test (or equivalent) whether you're losing people when you annoy them by popping something up on the screen.
And perhaps I'm an outlier. If the A/B test says you get more sales when you annoy the customer, who am I to argue (or it annoys me and not them). But it does mean you will have them as a customer and not me, and that's fine.
I don't think I'm wrong to use this as one of many indicators of how annoying a SaaS is going to be to deal with over the long term.
A favourite story[1] (and I can't remember where I read it first) is the WWII bombers that the US military were trying to understand how to protect by analyzing the bullet holes. But the bullet holes only told part of the story. Any bomber that made it home to be analyzed had only been hit in a non-critical place.
I'm not saying there isn't a place for chat, because I believe that they're absolutely is. A good, direct to the person chat, or unobtrusive ability to reach out is great.
Shoving it in my face and breaking the flow of what I was doing is not.
While I agree that HN readers aren't representative, I have a hard time believing that other people don't behave the same way when presented with annoying website behaviours (even if they later want the contact with the human).
I've seen behind the scene of businesses that get customers asking stupid stupid questions, so I also understand the where the zendesk 'are you sure this doesn't answer your question' comes from. Doesn't make it any less annoying when applied badly to expert audiences.
[1]:https://en.wikipedia.org/wiki/Survivorship_bias