You'll find instead that it will turn any community into an echo chamber. This sort of tone policing accomplishes nothing but belittling differing viewpoints and alienating users who may (publically or privately) disagree with charitable interpretations.
When the dust clears, you'll have a harmonious web forum -- in which no information is exchanged.
The fact that people have been saying this about HN for many years suggests that the argument isn't as strong as it sounds. What you describe is indeed a danger, but there are many dangers. Effective moderation must protect against all of them.
HN's way of balancing this is to require that comments be civil and substantive. Adding the principle of charity is simply a clarification of what that means.
The 'principle of charity' is not primarily about ethics or tone. It's about intellectual substance. It simply says that people should respond to the strongest plausible interpretation of an argument (or comment or phenomenon). What reason could anyone have for insisting on reacting to a weaker interpretation than they need to? I can think of a few, but none apply to a site that wants civil, substantive discourse.
When the dust clears, you'll have a harmonious web forum -- in which no information is exchanged.