elindholm
edited for content
It has nothing to do with being in a hurry. It is blatant lack of respect for the English language. In a hurry, I may mistype something. Your vs. you're and there vs. their vs. they're is beyond that.
It's beyond that if you make the mistake hundreds of times in a row. Anyone can make it once in a while.
My feeling is, if you want other people to take you and your thoughts seriously, you should show that you take your own thoughts seriously. Step One is paying attention enough to avoid obvious grammatical errors. Otherwise, you're just talking out of your [censored], so why should I pay you any attention?