If you've ever done woodworking, you'd appreciate the imperial system, especially when working with kerf size and whatnot. The imperial system was literally made for that kind of application. Rather, not made, but it emerged.

The imperial system emerged piecemeal as a series of domain-specific measurements, where each unit conveyed deeper meaning beyond rote volume, distance, etc. For example, an acre means much more than 43,560 feet squared. It means "roughly the amount of land that a pair of oxen can plow in a day". A nice domain-specific measurement that communicates something useful to the experts of that domain, in this case, plowmen, farmers, and lords of the manor.

With inches, an inch is about the length of your thumb. Imagine doing woodworking and measuring in thumbs - it's right there in front of you, easy to conceptualize and work with, an intuitive "bite-size" unit of measurement. Fractional centimeters aren't as intuitive to work with and conceptualize. 6+3/4 inches is a lot more workable than 17.14cm.