I think the issue is how people approach the purpose of conversation.
Many internet forum conversations take the form of arguing or debate. That is to say, the goal is getting to the bottom of a dispute showing someone that they are wrong (or learning that you are).
People who do this often fall into the habit of defaulting to this mindset and goal in conversations where this is not the purpose.
"no way, it must work" is a non-optimal but perfectly valid conversation starter. The problem is when there isnt follow up on the real point of the conversation (helping dad), because they treated the interaction as an argument to be won.
>My dad told me that he wants to dabble in programming, but MySQL isn’t compatible with his laptop. My response? "Yeah there’s no way that’s true. MySQL will work on anything." Instead of taking a look at this laptop and working on the problem with him, I just told him that he's wrong and he doesn't know what he's doing (basically).
The other example is even more telling:
>my ex-girlfriend once told me that hospitals can’t require their staff to wear N95 masks at all times -- only regular masks. I immediately said "I don’t believe that. They can probably do whatever they want." Instead of being empathetic toward a nurse after a 12-hour shift, I was more concerned over hospital policy.
The ex-girlfirend isnt looking for a spirited argument or debate after a long day. They dont care about who is right or wrong, or getting to the factual bottom of things. The author is dragging this mindset into a conversation where it is unwanted and doesn't belong.