And by posting (that type of suggestion) and not following the rule HN gets to also review what others think in terms of an idea.
And DANG or any mod can then reply if they want and others can see the reply. Instead of either ignoring or having a conversation or engaging with only one person.
As a general rule in business - my personal belief - born out over a very long time in business - is that you should not limit people when they are giving you free advice or suggestions using their own time. [1]
[1] If someone writes to the CEO of a business or an organization the proper response is not "Please send that to 'suggests@companyname.com" it's "thank you very much for the input we appreciate it".