I think this comes down to partly your state of mind at the time, i.e. how fed up am I with this lark, and also the sheer level of communication you can be having...
Join a couple of dating sites, sign up to Tindr and maybe go out and do some speed dating too, and suddenly you're having numerous little exchanges with lots of different people... It's bloody hard work to come up with decent conversation with new people over and over and over again, which I think is why there is the proliferation of "how's you ?" because a) it's a way of starting a conversation and b) the person might be all chatted out...
It's not even like your having an online chat based on shared interests ( I'm thinking of some of the online friendships I made through gaming which was the bridge to start the conversation and it followed from there ).
Then there is my favourite comment on profiles "don't just say hi, put the effort into saying something original"... Really ? Say something original when the profile tells me nothing at all about you other than "if you want to know just ask"...
Of course there are lazy people of both sexes. There are women that think they need put no effort in at all ( because men only want a pretty face right ? /end sarcasm ) and men that just think that spamming enough women with "hi, wanna see my " will get at least one response, but in general, I always think that most people fall into the two categories I outlined in my first paragraph.
I think the truth is though, that if you're finding conversation hard, they're not that into you and you're not that into them ( or OLD in general ).
RLD