I'll come right out and say it: "incorrect" punctuation and spelling is artistic in the world of design.
I have a Bachelors in Linguistics, and one of the most important things I learned was that there is no actual authority on language. It is liquid, it changes, and as long as you can successfully communicate your meaning, you shouldn't be ashamed of your grammatical knowledge. In fact, like most people, I skew words, make up terms, and spew out nonsense on a regular basis... and people rarely call me out on this doofy behaviour.
Despite this, I tend to try and maintain correct (mainstream?) spelling and punctuation... except when I'm designing. For some reason, as soon as I add any typographic element in a piece, I opt for no capitals, or ALL CAPS, or even run-on sentences. Sometimes I have a reason- I need the to draw the eye to the words, and these changes will create emphasis. Most of the time, I feel like I'm breaking the rules just to appear more artistic.
Is that so wrong? I really don't think so! I think it can look elegant when letters are small and equal in size. It's a personal thing, it adds flavour, like texting words such as "wanna", "gotta", and "whatchoo". There's no REAL point, and yet it's a habit that I (and many others) do.
In the end, I think it's perfectly harmless. The important thing is to remember that you have a purpose for deviating from the norm when designing for someone else! What does everyone else think?