One definition of blunt is ''"dull blade, make less intense, dull down"''. 

However, blunt also means "direct and straightforward in speech".

To me, being ''direct'' with speech is being ''sharp'' and ''precise''. This contradicts dullness!

{Perhaps your confusion results from your interpretation of ''direct'' as meaning ''precise'' and ''sharp''.  To most people, ''direct'' with speech means getting straight to the point, skipping all the flowery stuff, the 'sirs', the magic 'please', the circumlocution that often comes when talking about uncomfortable topics (a dead relative, sex to a child, a person's bad habits to their face, etc.).  Contrast this with ''precise'' speech which generally refers to speech with definite (as opposed to ''vague'' or ''ambiguous'') meaning, and ''sharp'' speech which generally refers to speech caustic, biting, acerbic, harsh and often abrupt in both content and mannerism.}

[''Direct, straight to the '''point'''. Visualize a point. A sharp knife with a point...'']

{'the point' in speech has a very different meaning from 'pointed' speech.  English is tricky like that; you'd do well to learn a bit more of it every day.}

[It is not very different in my mind. In English, when one is to the point - he is direct, precise - just like a finely cut tool or a sharp knife.  For example: "He is wrong about points." or "He is right about points." That is precise and to the point. Just like a knife. Point form. A dot. A dot is very pointy too. When we make point form notes (to the point), we make dots that are pointy. It is related, they are not ''very'' different to me.]

{When actual use of English does not match what is in your mind, you need to learn more of it.  Saying "you are wrong" is, with exception of some contexts, not precise (wrong about what?).}

I don't like the fact that the word ''blunt'' is overloaded to mean quite opposite things.

See google and type in define:blunt for a definition, and you will see what I mean.

A nice quote:
*''"About the use of language: it is impossible to sharpen a pencil with a blunt axe. It is equally vain to try to do it with ten blunt axes instead." -- Edsger W. Dijkstra''

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''Alright. Enough. I have had it. Get to the point already:''

http://www.therebelalliance.co.nz/assets/Show-Images/ANightOfFrenchMayhemBosom.jpg

''Make some point form notes. And sharpen your pencils.''
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See CriticizeBluntly, CriticizeDiplomatically