I think what the author is driving at is: when multiple programming languages exist in the same space, it's not a very effective use of your time to learn all o

I think what the author is driving at is: when multiple programming languages exist in the same space, it's not a very effective use of your time to learn all of them. If you know Python and Perl and you teach yourself Ruby, you probably won't learn very much. If you then teach yourself Lua, Javascript and PHP, you'll learn progressively less each time. I was surprised to see this particular brand of negativity in the comments. I thought the post was trivial, not controversial.