"maker fair" is a generic description, something that can't be a trademark as it's not distinctive (unless it's for a category of thing that's completely unrelated to the term, like you could use it asa TM for apple juice, or something).
The USPTO doesn't agree with you. [1] More likely the examiner considered it "suggestive" which can be trademarked if it's well-known. At this point it is even incontestable. [2]
Meaning they're relying almost entirely on "maker" to provide distinctiveness.
If the USPTO has any inkling of sense they'd realise "maker" is a standard English word that is being used for its ordinary meaning (someone who makes things), and does not give any indication of a specific origin.
You can't prevent people using common words, with their ordinary meaning, to describe their own products by registering those words (that's common across all TM systems). Any attempt to sue someone for running their own maker fair using the words maker fair should be dismissed by asking the judge to look up the two words in the dictionary.
