Advanced misspelling

So I think we all understand how confusion can arise with where apostrophes go; it's a little bit complicated and easy to miss if you didn't really like English lessons at school.  But how can a sign writer not be able to spell fairly simple words?  If you weren't that good at spelling, wouldn't you at least have a dictionary in your pocket?
What about the man who owns the shop, the one who paid the man who created the sign- was he happy about it?  Didn't he use glue or epoxy or something that said on the tube it can be used to repair stuff?

Not knocking it, it's just that my brain is actually boggling at the moment. Properly boggling.

At least they do watch "bands". I need one of those.