If you are chatting in real time, like on skype, I think you are right. But this site is more like email. People reply when they have time so there is no need to let people know you are signing off unless you are having a very active conversation.

I don't agree, usually I don't say "Bye". It's stupid. I'm here for moment, so I like to leave italki with "open conversation". It doesn't mean that I don't have respect. 

I think I understand what you said but also I would like to share something with you, in short, "to err is human, to forgive devine."

Sometimes we feel like we WERE being mistreated, only according to our own standards, the second nature. We don't know how often and how much we MIGHT have mistreated others as them us, unconsciously and subconsciously.

Once a (false) victim mindset is rooted and lasting too long, the body get sick, mentally and then physically. So leave it once you sense it and when you can.

The world will be a true machine when you find no one thinking differently, doing differently. You may appreciate that one day, I hope.

Being happy is your own responsibility. It has nothing to do with others! :)

I guess I know what you are trying to express and that often frustrated and disturb me when I am trying to practice a language with others. Have you met anyone who was talking to you and you were seriously answering to his/her questions yet he escaped without so much as a signal or farewell. That is very alike to the situation face to face conversation you just leave without saying a word. Once in a while, in some state of affairs, that is a sort of insult or a rude act at least. Perhaps some people do not consider that is an impolite behaviour and they just get into the habit of such a behaviour, but think of the concrete reality , will you do the same way as you did during online chatting? Probably that reminds us to think more of so-called politeness.

Well, you may do as you like or as you used to be able to do. However, your partners have the equivalent right to do the same way as you did. 

محمد عمر, I'm a big confused. Do you mean when chatting back and forth a little here at Italki or do you mean in a conversation through skype?

When I'm typing back and forth with instant messaging on Italki I never say goodbye. Sometimes I'll put a cute sign-off for fun, but the idea of typing back and forth is that we can come and go and respond whenever we have time. That's the beauty of it. We can have an open continual conversation over months or years without having to stay in our chairs the whole time. I can pop back and forth when I have time. 

During an actual conversation by skype, either just by sound or with camera, then yes, it would rude just to disappear without saying goodbye according to my culture. With the chatting on skype, that depends on how you and your partner use it.

I wonder if this a cultural issue?