If a writer is not using punctuation correctly in his articles, how would that negatively affect on his reputation?

Punctuation is very necessary and adversely affect the meaning of the order and carried out by

If you mean in the Arab region, it will not affect in his reputation. Because A very rare of Arabs who can recognize, understand and use the punctuation...  

His reputation will be harmed especially if applying to a job.

Writers cannot have punctuation mistakes, it is their job to write properly. 

Punctuation marks are not useless while creating a text. To make your text easy to understand, you always need to punctuate it properly. Otherwise you'll not find a reader for your writings.

Thanks

Agree with colleagues answers

Thank you mis. Samar

I agree with my collragues answers

Look at the following sentences.

1] No teacher is present in the staff room.

2] No, teacher is present in the staff room.

The first sentence shows the absence of any teacher in the staff room.

The second sentence negates first and tells the presence of a teacher in the staff room.

Hence, at times, lack of proper punctuation entirely changes the meaning of a sentence or an abstract. To write perfect English, knowledge of punctuation is indispensable.

There are two different possibilities: (i) His readers will take him to be just a beginner, not an expert in his field, (ii) Some readers might consider the article plagiarized, cut and paste from others and posted in a hurry without correcting the punctuation errors.   

Both the scenarios are harmful for a scholarly reputation of the man in question.

Do you know how plagiarism is recognized quickly at a glance? Through punctuation marks! 

.His reputation will be harmed especially if applying to a job