What if the pilot can't spell, and has a very basic grasp of written language? Yes every pilot ever has perfect english skills. You would think so, but going by endless posts on the forums, it seems to be a remarkably common occurrence that pilots' (commanders) spelling and comprehension weirdly aren't always perfect.
But you are right; let's ignore one context for a hurried message to make sure it's "correct"; I'm sure you've never typo'd an SMS, tweet, facebook post or message in the history of ever, including potentially being under duress or stress, either - right?
edit: my point is yes the messages perhaps should be spelled correctly, but humans tend to not always spell correctly; replacing one 'immersion' concern with another just makes CMDR KOFEYH want to upend buckets over people's heads.
My point is: However you wish to dress it up these are not written by 'pilots', they are written by paid employees of FD. It's just sloppy writing and if they can't string together a few basic sentences in English then it makes one wonder of the calibre of the people on the team. There is a vast difference between a user quickly scribbling a tweet or forum reply and an employee sitting at a desk in company time being paid to enter content into a game. When the game has so little depth and the devs then rely on text to add 'content' you'd think they'd at least make an effort to get it right.