Not everyone can figure out a doctor's prescription. Because, well, 99 out of 100 times, doctors write in some illegible script that only your pharmacist can understand. Perhaps that's the reason why the Union Health Ministry decided to bring in a gazette notification asking doctors to write their prescriptions in capital letters!

There are plenty of jokes on a doctor's handwriting but how is it that every doctor's handwriting is equally bad? 

Well, this doctor on Quora seems to have an answer and it does make sense! 

Here are excerpts:

Source: thehindu.com
I got first prize in handwriting competition in school. But, now. Holy lord. During exam, one can call the first page of my sheet as etched by a craftman. A damn perfect cursive writing. Beautifully written words. Later, even I can't read my own stuff.
Source: brasildiario.com

Well, seems like a legit reason. 

Now no one dare joke about doctors' handwriting!

You can read the rest of the answers by doctors on the thread here