Personally I don't mind spending several hours solving a problem over "async communication" if that means I'm free to work on other stuff while the other party is formulating a response. Then I also get the benefit of having something in their writing to refer back to.
The kind of person who takes hours to explain something in written form are unlikely to explain it in 3 minutes in person. More likely, they set up a meeting where they waffle on about an issue, expecting the receiving end to distill some valuable information from their ramblings, and then inevitably end up complaining when the solution doesn't match their expectations (which of course were never formalized anywhere).
