I’ve only had it happen once, out of at least eight online-dating interactions that did eventually lead to meeting in person. (Of the remaining seven, there was one where she kind of had that reaction upon meeting me).
It’s important to put it into context: there could be 15 email exchanges and phone calls in which things were heating up and then a conversation take place that made me feel like pulling back and not thinking of that person as warmly. So the fact that it can happen when you meet someone face to face doesn’t entirely mean it’s all about the difference between online + phone communication and face to face communication — it can just be that that’s the situation y’all were in when the intimacy-destroying conversation took place.
Generally by the time folks decide to meet in person, they’re interested in hanging out for a longer stretch of uninterrupted / ongoing interaction than they’d had via emai or phone. That may not be true for everyone (I had chat sessions of over an hour occasionally and some folks I know do telepone calls of over two hours) but I think it’s a fair generalization. First in-person date can be dinner and the rest of the evening. Not always, but it’s likely to be a quantum leap in the amount of interaction that takes place.
That means there’s a lot of opportunity for something to take a different tack when you do.
The other factor mostly applies to email compared to non-written (and would perhaps apply to telephone as well as in-person): some people are fascinating and intriguing when they write, when they have time to shape their sentences carefully, and come across very differently when it just has to spew out of their mouth in real time.
The thing is, when you get together with someone and decide to keep seeing each other, you’re most likely going to have the balance of your communication be in person from then on. So if the interaction is hot and exciting via email (and perhaps also phone) but far less so when together for an evening in person, it’s not like you’re going to shrug and think “Well, we should just go back to emailing, that was hot”. I mean, I suppose folks could but realistically we don’t. The exception would be when you’re flirting with someone two states away and in-person togetherness is going to be somewhat rarified no matter what happens. Even then, the romance is about the imagined face-to-face encounters and if they’re not so good that’s going to take the zing out.
I’ve never, ever had it be the case that it was lack of in-person electricity that did us in. The one that went sour on me did so because she seemed standoffish, flaky, distracted, not very present for the interaction, whereas when she wrote, she was bubbling over with rapid thoughts and vivid interests. The other one I mentioned where it was the other person who decided “naah, not for me” when we met in person, she said specifically that I seemed younger in person than my chronological age and she was already 8 years older than me, and in person it definitely mattered a lot and ruled out things going anywhere.