Kindly isn't Kind

I came across enough use of the word 'kindly' almost all in indicrimately places.

(extracted from http://www.goodenglish.org.sg/)
Did you know that ‘kindly’ is not a very polite word to use in your correspondence?
Below are common examples of the word ‘kindly’ being used in emails, letters and notices to colleagues, clients, customers and business associates:
‘Kindly complete the reports in time for the meeting’ , ‘Kindly pick up your parcels by 7pm’
‘Kindly send me the cheque by this week’ , ‘Kindly pay at the cashier’ , ‘Kindly take off your shoes’
But did you know that 'kindly' isn't the right word to use in the above instances?
Avoid Using The Word 'Kindly'
When you use the word ‘kindly’, it often means that that you are annoyed with the person you are writing to.
Using the wrong words can confuse or anger the people we are communicating with.
It is better to use 'please' instead of 'kindly'.
Replace the word ‘kindly’ with 'please' in any of the above examples and you will sound friendlier and definitely more polite.