In informal online writing, using full stops has become an optional choice, which means that using full stops requires that you choose to do so, which means that presumably you have something to communicate by that choice.

Generally speaking, using full stops is a sign that one is Very Serious; it's the textual equivalent of how, when someone is angry, they will close doors harder.

That is part of a real convention in active use, influenced by the medium of text on phones and computers. People replace full stops with newlines/message breaks, and over time they start to repurpose the now-unused punctuation for emphasis.

It's not surprising that new linguistic conventions cause confusion, but that doesn't make them something to deride.

Related: https://www.theguardian.com/technology/shortcuts/2015/dec/09...