This post is just a quick hack

Today we walked from our flat through Bethnal Green to Hackney. On the way, we walked by Überhaus, which, despite its ludicrous name, may become London's answer to Rat Wharf. I finally found out how the term "hackneyed" arose: In the middle ages, Hackney was rural, and became famous for its horses. World Wide Words goes on:

Horses of the hackney type were often worked heavily, in the nature of things that were hired out to all and sundry. So the word evolved in parallel with the previous sense to refer figuratively to something that was overused to the point of drudgery. By the middle of the sixteenth century, hackney was being applied to people in just this sense, and was abbreviated about the start of the eighteenth century to hack, as in hack work; it was applied in particular to literary drudges who dashed off poor-quality writing to order—hence its modern pejorative application to journalists.

Hackney horses were also widely available and commonly seen, to the extent that they became commonplace and unremarkable. So yet another sense evolved—for something used so frequently and indiscriminately as to have lost its freshness and interest, hence something stale, unoriginal or trite. The adjective hackneyed communicated this idea from about the middle of the eighteenth century on.