Kudos to observant tweet-der (tweet reader? @wfucass11)) for picking up a there – they’re confusion from ESPN’s Seth Davis (@SethDavisHoops).
Davis’ response raises an interesting question: what is the imperative of correctness in the face of so many different (technological) contexts? Clearly, a tweet is a different medium than a published article in a print magazine and I wouldn’t necessarily begrudge a tweeter a mistake here and there but this is analogous to my frustration over the common signature (and its variants) ‘Sent from my iPhone / Please excuse any typos.’
There are two groups of people in your correspondence list: those that are professional contacts whose opinion of you you care about and those that are personal contacts whose opinion of you is set, independent of your grammatical proclivities (and there is of course some overlap). For the former group, you (I would hope) would edit even the most informal of correspondences; appearances and correctness matter. For the latter group, it doesn’t matter anyway; you’ve known each other enough that correctness is more a luxury than an imperative.
What’s left then is the psychology of the signature. If the signature doesn’t matter (because you’ll either correct or you don’t care), then it is reduced to a message. And the message is that you’re too busy to proof your work or to care about it. Again, let me reiterate, you will proof your work for someone whose opinion you care about and you won’t care about proofing for someone whose opinion is already set, so why include the signature except as a semantic signal that you’re life is so busy that you can’t be bothered with something as pedestrian as grammar?
That’s not to say of course that Davis should be bothered or isn’t otherwise bothered but the excusing of grammatical mistakes (whether by the writer or the reader) brings up all sorts of questions that are worth exploring.