Complicating small matters. =X

I argued a little with my friend today, because of some small matters. I would say it is an argument, because both of us are not agreeing with each other with certain issues. I am only going to share just a little part of the entire scenario.

Today my friend is having some usual conversation with me like how we usually did through text messages/whatsapp.
After I didn't reply for about 40 minutes (because I was basically busy with my stuffs that I didn't check my phone), I receive messages that totally messed up my mood.

"Why does everyone doesn't know the etiquette of replying a message?"
"GOSH!! where are the smart people with smartphone nowadays"

I felt really angry and sad at the same time reading messages like these. But I am glad that I choose to not use harsh words to reply and continue to talk normally. If not, some bad things are going to happen!

I am feeling angry as I am not someone that can be with my phone 24/7 and I did not ignore the messages on purpose after all. And it is a sadder feeling to get harsh messages from your closed ones. I know sometimes people think that they are close to you, then they can say whatever they want or do whatever they want. But no matter how close a relationship is, I believe it is still important to take care of other people's feeling despite just our own.
(People that are usually closer to you hurt you the most without realization. So true.)

I am not saying in the above scenario who is wrong or who is right.
But I believe there is a better way to express ourselves without being harsh towards others.
I know it is frustrating to send people messages and not getting any response.

But is criticizing/scolding/teasing/hurting others necessary? How can it help with the situation at all?
There is always a better way to say it by expressing ourselves fully but at the same time taking other people's feeling into consideration.
(Eg. I am really frustrated not getting any response from you, can you reply after u see the message?)  or even better ring the person up right away to talk about the stuffs if it is really urgent/important?

Why criticize/scold/tease/hurt others when there is better ways to convey the messages to the other person? I don't get it.

I don't think anyone likes to be yelled or treated poorly! I know sometimes friends may tease each other once in a while, that's fine. But boundaries should be set and not crossed.
No one in this world likes to be teased frequently, not being appreciated and respected.

Anyway there may also be a possibility that I am the sensitive one and my friend probably doesn't mean anything. Who knows? haha simple stuffs yet I make it complicated.