I always find people like you hilarious. You throw the whole thing out because you find a single misspelling? I’d submit to a small minded person such as yourself that you’d never be able to accept ANYTHING printed if that is your lone criteria. Just about every magazine, every newspaper, every book has SOME violation of spelling or grammar.
Now, if every other word was spelled wrong, or the grammar was blatantly bad throughout, I could see your point. Unfortunately, you make yourself look small and petty otherwise.
Now, instead of acting picayune perhaps you’d like to actually ADD something to the conversation for a change?
I work in a business where we receive written material from professionals all day long.
If we receive something that contains obvious grammatical or vocabulary errors, it starts the thought process: "What else has this guy done wrong?" At the very least, the proposal is going to be gone through with a fine tooth comb to uncover the other potential errors. They don't usually come singly. And when competition is strong, that can tip the balance against the writer.
In addition, a writer who presents something for publication with such an obvious error (and it's not a misspelling, by the way, it is apparent ignorance of a commonly used English phrase) is demonstrating that he doesn't care enough about his work to proofread or simply step across the room to consult a dictionary. Not an impression you want to create when you're trying to persuade people.
The internet is a useful tool, but it is full of semi-literate sludge, and the process of winnowing out the sludge from the useful material is both quick and severe. Why put yourself at a disadvantage with something that is easily corrected?
Just a word to the wise.