I would abstract this topic to: talking to your users is important, and phone is a high-bandwidth medium.
In particular, it seems like this developer recognized that phone connects them to their less technically savvy users, who - by being most different from the dev himself - can give him the most valuable outside perspective. Depending on your market, if you're trying to sell into non-techies this could provide hugely valuable insights.
In general, the closer you are to the development side of things, the more you have a very specific (and I guess "correct") model of how your system works. By default, all of your documentation/support forms/etc implicitly reflect this model. But if your users model the thing in their brain differently, then your help/form aren't the most helpful in educating them or eliciting their true feedback/problem.
One final thing - I have seen 'magic' where developers who chafed at tickets coming in from support staff (withdrawn, user error) would all of a sudden get excited about rebuilding something when the user themselves or even the support person, just explained in a higher-bandwidth way why the problem is real. It's easy to read a ticket and go "oh that's dumb, they should just do X" but on the phone/in person you go more into like "oh, this is a really reasonable/nice/smart person who's trying to use my system to do something important, and it's not letting them."
In particular, it seems like this developer recognized that phone connects them to their less technically savvy users, who - by being most different from the dev himself - can give him the most valuable outside perspective. Depending on your market, if you're trying to sell into non-techies this could provide hugely valuable insights.
In general, the closer you are to the development side of things, the more you have a very specific (and I guess "correct") model of how your system works. By default, all of your documentation/support forms/etc implicitly reflect this model. But if your users model the thing in their brain differently, then your help/form aren't the most helpful in educating them or eliciting their true feedback/problem.
One final thing - I have seen 'magic' where developers who chafed at tickets coming in from support staff (withdrawn, user error) would all of a sudden get excited about rebuilding something when the user themselves or even the support person, just explained in a higher-bandwidth way why the problem is real. It's easy to read a ticket and go "oh that's dumb, they should just do X" but on the phone/in person you go more into like "oh, this is a really reasonable/nice/smart person who's trying to use my system to do something important, and it's not letting them."
Gets a totally different type of results.