I read this and laughed, then laughed even more as I saw the comments of most of the guys. I wasn't going to respond, but after all the comments that I saw I just had to throw my penny in.

As a male, I get it. Apps are how should I say pointless. Most of the people on any of them at any given time (both genders) are at best looking for something, that is either a one nighter or conversation. So, to the point saying hi, like I said as a male is most of our ways of seeing if she is a waste of air, or worth our time actually conversating with, or getting in bed with (for the majority). So, in a sense if we don't get respond it goes more in our favor than anything. Not wasting time on something that isn't worth the time typing back. On the females side I can see that a simple "hi" is also a way of as you said "filtering" which in sense also filters out the guys that want something more than a quick lay.

In my past experience on dating sights. I have ALWAYS said "hi" if I was somewhat interested. If I was very interested I would say more, but as I have deleted and moved on from the dating scene (happily so) I see it both ways.