Why did Picasso draw his paintings like stick cartoons?

None of his figures look like stick figures!  

Look, this is what young Picasso was capable of at just 15:

https://www.flickr.com/photos/89235234@N00/4356587...

Art in the late C19th/ early C20th had a crisis.  Artists asked themselves what art was for in an age of photography and mechanized mass (re)production.  It certainly wasn't to faithfully document the world anymore, so they travelled inwards, exploring the psyche, backwards, exploring primitive art and its meaning to the peoples who created it, and forwards, exploring the materiality of mediums.  The horrors of WWI stemming from too powerful new technologies applied to old warfare methodologies made these questions all the more urgent to artists.  Cubism is just one expression of these questions and explorations:

https://en.wikipedia.org/wiki/Cubism

Try to copy Picasso.  Not a pastiche, really study the piece you're aiming to copy.  You will soon find that only the man capable of producing the above self portrait at 15 had the skill and subtle eye required for those cubist portraits. They are neither simple nor sloppy.

His unique style. 

Its called Cubism Art and Picasso was one of its creators. In his later years he mass produced his art by using dozens of artists and craftsmen.  He would check out their work.  If he liked it he would sign it. 

He was quite capable of producing conventional art, but if that was all he did we would never have had something as brilliant as "Guernica" - but either you get it or you don't. Fortunately many people did.

He was a great admirer of the British artist ' LS Lowry', and followed his style when depicting the human form.

Yes, Picasso bashing has become fashionable among the less than sophisticated art spectator crowd.

why dont we have famous singers from the 1600s?  because no one could record them of course..  this we can record...not only is it art (subjectively) but its also history

also style...those who do something different tend to stand out

Bigger question, why did people pay millions for his second rate, third grade scribbles?