>>8

so I've set a goal to try to actually become offline friends with my online friends at some point

Then you're free from what the post describes. Your vector is pointing toward mutual experience, eventually. Most online relationships that people entertain do so with a bit of insincerity, ironically. They would never consider the person more than someone to talk to, as you have. This leads into my other response.
>>9
You will always regret everything you do. This fact seems to be the only solace I could say here.
The important thing to do is to emphasize the benefits of what you've done and minimize the benefits of the other side. For I'm sure you'd just as strongly regret bothering to form online relationships.
In my opinion, there is little to regret especially if there is no intention in seeing them in person.

The online friendships you crave are far more likely to fail, and the sincere connection you seek is rarely found in online communication.

Far more likely to fail because of as you described. The complete insignificant barrier of entry for the average internet user nowadays.
I scroll through scattered forums and wonder why do I still have faith that some post worth reading will crop up?
And if it does, when compared, would not a book more likely preclude dissatisfaction?
For all printed words have the same auditing, and all authors know what it means to name the work after yourself.

As for sincerity, it is easy to mistake honesty and words for good intention and action.
Take for example someone repeatedly saying "I love you."
If they genuinely did feel that, would they not instead show it through their actions? This is a chief principle of anyone you come in contact with.
And the irony is, for online relationships, all one can do is say I love you. Repeatedly and without feeling. Without feeling?
Well, have any of you ever caught someone on the phone doing something else, like doing the dishes, while you were divulging something vulnerable?
Your thoughts aren't really priority, is what was conveyed. That feeling of betrayal that could follow is impossible with online chatting, since it is asynchronous, but rest assured most of the indulgence one does in conversation is only but a part of a circle of actions chronic internet users do.

The half presence described does not just mean physically, it also means even to those you talk to. For the stream of someone's words eventually appear only as words, and as you become more "of your self" and exposed, the less you can easily remember there is someone on the other end. Everything is easy to interchange. Even the posts you read online. Are these your words or mine? Why value my words more dearly than a friends? You aren't you say, but you still read this, no? How can one begin to profess loyalty to an online friend if you share the same actions among strangers? How is an online friend different from an online stranger? The amount of time you could put in seems negligible, since, as shown earlier, the time is nothing. There is no return on investment, for there are no memories to invest in. Mutualy exclusive lives. I suppose the only distinction is how much you know each other's story - but this seems to be more of a voyeurism than of a concern for another person. And how painful it is to genuinely care, among either wolves who want your attention until no longer they find it tasteful, or among the people you love but in all likelihood can never be anything more than a pile of words.