My strategy when I meet a girl I like is to exchange numbers, but have no intention of contacting them. The girl always has to contact the guy first. It's just how it works.
Trust me, this is not true. Initiating contact is not only acceptable, but quite often preferred. Generally this approach is just protecting your self-esteem.
No, it's a sign of respect. In these days of Tinder, girls are used to guys hitting on them all the time. By not contacting them, you are actually sending a message.
There are guys I meet that I think could become my best friend or a great future co-founder. But I never call or text them, because I get busy with work and life.
Not only that, it seems like an ineffective strategy. I can't imagine you'd get more than a 10% response rate from this - and that's if you are exceedingly attractive. If you are just an average joe, this strategy basically does not work. If I had enough things going on in my life though I'd also always wait for the woman to contact me first because I've been used and manipulated too many times and don't see most women as worth the effort.