Why do people struggle to spell school?

The local news has just ran a story of contractors painting the word "shcool" on the road. However this isn't a one off, all around the world you can find the identical story, the word school incorrectly spelt on roads and signs.

So why do you think it's a reoccurring problem? Are people simply dumb or is it more complicated?
People are dumb
It's got a secret hidden meaning
They're trying to be funny
They're sending messages to passing ufos
Select gender and age to cast your vote:
Why do people struggle to spell school?
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