The reason is simple...
About 5% of guys actually have the balls to do this.
What does this mean? That you automatically stand out in a major way.
I was literally just walking here in Madrid before my flight tonight and saw this gorgeous Spanish/Mediterranean girl walking next to me. I said hello a couple times before she turned, and we struck up a convo right there. About five minutes long. Turns out she's a flight attendant - Italian, but based in Barcelona. I tried to pull for an 'instadate' but she had a flight in a few hours. Here's her IG cover photo.
As far as tips go, check out the book "Day Bang" by Roosh. I read it years ago and changed my whole approach.