3 Reasons reason why "S" gets kicked out

Ever wondered why was the letter "S" spared from the names of some numbers? Why aren't 200, 300, 400, etc. called Two Hundreds, Three Hundreds, Four Hundreds and so on?

Perhaps, the letter "S" was too overworked among the set of consonants.

My belief is mostly based on my own baseless logic and one fact. 

1. Most of my friends' names begin with the letter "S" or have the letter "S". For instance, my friends include Sushmita, Sudakshina, Sandeep, Sagarika, Sanjeev, Sakshi, Salma, Saru... the list is long and as I would have said in a speech had I received an award, "I am sorry if I missed anyone's name here!"
2. The plurals! Poor "S" got its ass kicked like how! Thank God for Men, Women and Children who saved some usage of the letter's plural overwork!
3. I also believe in the fact of life that Men, Women and Children need facts to believe in senseless discussions like this one. So I did my research after I completed the 2 points above and listed below are the findings (I was quite right you see!):

The relative frequencies of letters (Source: http://www.cryptograms.org/letter-frequencies.php)

e     0.12702
t     0.09056
a     0.08167
o     0.07507
n     0.06749
s     0.06327

So let's ignore "T" and "N" for now for the simple reason that the following titles for this post have no punch:
3 Reasons reason why "T" gets kicked out
3 Reasons reason why "N" gets kicked out

And hence, my logic for "S" is justified. Poor Soul is too overworked. It is used billions, millions, thousands and hundreds of times, so much so that someone coining the names for numbers empathised with it and decided to kick it out from stuff like:

Two Billion (and not Two Billions)
Three Million (and not Three Millions)
Four Thousand (and not Four Thousands)
Five Hundred (and not Five Hundreds)

 So the next time you write a cheque for me for say some Nine Million Eight Thousand Two Hundred and Ninety Dollars, and skip the letter"S", I will consider you a philanthropist for saving my "S" ;)