Most often, yeah, that's the case. Sometimes it's one extra keystroke (your -> youre, two if you want to add the apostrophe), but words like definately, tommorow, and rediculous have the same number of keystrokes/letters/effort as the correct counterparts.
This is a bit of an extreme example, but it's similar to me to going on a date and not taking the time to comb your hair or brush your teeth. Sure, it takes only 30-45 seconds if you're in a rush (a fraction of the time you'd spend showering/getting dressed, i.e., probably the same amount of effort it takes to press a few extra keys to spell a word right during your average-length post), but some people might just be lazy and not do it. Then, when people ask them why they look the way they do, they just say "eh, I could have, but I was lazy". Sure, it's their prerogative to do this, but people will form opinions (typically negative ones) about it.
No, I'm not saying spelling on the internet and going on a date are of the same importance, but the parallels are there for me.
Plus, if a person spells like this on the internet, they form bad habits and it becomes ingrained for when spelling really does matter (say, emails with a boss/professor or resume/cover letter stuff).
I still say, if you know how to spell a word, why would you intentionally spell it wrong? It just makes no sense to me. Thus, I'm left to believe that people who spell words wrong, aside from obvious typos, simply don't know the correct spelling or usage of a word. I don't see why this isn't a fair judgment.
Disclaimer: I'm not mad, nor am I frustrated. I don't mean anyone physical or emotional harm by this. I am not saying anyone in this thread is ugly or has bad hygiene. My intention is not to get people pissed off at me. I'm honestly curious why someone would intentionally spell a word wrong. To me, that's like intentionally going out into public with your zipper down.
