While underground wires do make it look pretty up above, there are negatives involved in that they invariably fill with water and then freeze up in the wintertime. Try running new wires through a frozen-up underground conduit sometime.
There's also the expense of having to dig everything up should you ever have to do some kind of major repair or changes.
Not an expert on the subject, but there may be more to Halifax's "lack of vision" than is readily apparent while admiring the clean appearance of a wireless street.