If 90% of traders fail, why not just do the opposite?

I think that if traders trade exact opposite way they are trading would turn the 90% losing traders into winners? ie instead of going long, short, and vice-versa.

It seem that the best way to trade would be to share real time strategies (with bad, or really bad traders) and simply do the opposite of them? Seems a great way to make money!

Or do the opposite of what you intend to do..i know it would have worked for me atleast on paper..

If 90% of traders fail, why not just do the opposite?