I know what you mean, I think we all feel a little intimidated by watching guys like that rattle figures and dates off the top of their head like a machine. Maybe we all can't be just like that, but there is a lot that anyone can do to better themselves and their presentation.
No offense here but I gotta be honest with you, the way you type really really makes you look bad. Nobody takes a post with poor grammar seriously, even if the content is meaningful. That first impression turns a lot of people away from even reading it, and if they do read it they will automatically be incredulous towards the ideas presented. It comes off not only as dumb but also uncaring, like the bare minimum effort was put into typing it. If someone can't put effort into their own words, then why should we put effort into reading them? Moreover, poor grammar makes it much more likely your point will be misunderstood.
Grammar isn't just some arbitrary thing the English snobs made up to feel self-important about, it all serves a purpose. Punctuation separating ideas makes all the difference between misunderstanding and clarity. Commas are underrated even. Proper capitalization and spelling also help not only with clarity, but ease of reading since proper nouns stand out. You are not only putting off people from reading your comments, you are actively making it much harder for any willing readers to make sense of your words.
I'm sure what you are saying is perfectly self-evident in your own mind as you type it, but imagine a reader who has no context for what you are saying, misunderstandings are much more likely than you probably think.
Also girls hate poor grammar. If you haven't noticed, the vast majority of girls have superior grammar compared to guys their age. I'm telling you, really poor grammar is like repellant to girls. Most of them take it more seriously than me. And those that don't... you probably don't want.
@Firegirl26 wouldn't you agree?
Perhaps most importantly though, is bad habits like this are harder to break the longer they persist. If you ever want to be taken seriously at a job or talking with a girl online, or talking politics online, practice typing properly. Eventually its going to be harder than you think to force yourself to do it properly when you have to. I probably make way fewer mistakes than someone who only types properly when they absolutely have to. I always use proper grammar, even if I'm on instant messaging or text, its second nature to me and doesn't feel inconvenient. And I think that's served me well in all of my interactions, both important and unimportant.
