Busman's Holiday

It's one of my favorite English (as in Merrie Olde England) phrases: busman's holiday. As a child, I was able to elicit the meaning from the context in which I normally read it: to take a busman's holiday is to work, or at the very least to visit your workplace, on your day off. But what is a "busman", and why do they work on their days off?
You can read a comprehensive attempt to explain the phrase here, but I'll excerpt the relevant part:
Busman’s holiday is originally British, dating from the end of the nineteenth century. It initially spread to other countries through reports of London affairs and then caught on locally. It appeared in the Sunday Times of Sydney, Australia, in May 1896 and the Auckland Star of New Zealand in October 1902. It reached North America in 1909. It’s now known throughout the English-speaking world. . Some writers on etymology have got into a mess trying to explain it. . A typical story appeared in John Ciardi’s A Browser’s Dictionary in 1981: “British drivers of horse-drawn omnibuses, becoming attached to their teams, were uneasy about turning them over to relief drivers who might abuse them. On their days off, therefore, the drivers regularly went to the stables to see that the horses were properly harnessed, and returned at night to see that they had not been abused”. A similar tale is told by William and Mary Morris in The Morris Dictionary of Word and Phrase Origins, except that they assert that the most caring drivers, should they have any reason to fear abuse would occur, would sit among the passengers to observe the relief driver’s behaviour. A related explanation was given in the Brownsville Daily Herald of Texas on 2 September 1909: “When a London omnibus driver takes a day off it is supposed that he spends it riding around on the top of a friend’s ‘bus, seeing how he does things.” . Other writers are justly scornful of such sentimental explanations. Anyone who has looked into the history of nineteenth-century London buses will know that their horses were no better cared for than any other working nags and that they were often sweated to death. . The most plausible explanation given by writers who seek to explain matters is that a popular day out among working-class Londoners in the late nineteenth century was to make an excursion by bus. A bus driver or conductor who went on such a trip was said to be taking a busman’s holiday. . However, the earliest examples point to its instead being humorous urban folklore.
I had a relatively short lunch hour available today, so I decided to run over to the Potbelly sandwich shop where I am an occasional lunchtime "musician". The best parking spot in the lot was available, so I took it without guilt; when I'm playing there, I'm expected to park as far away as possible. I had a variety of conversations with the staff, some of whom thought I was there to pick up the Tuesday shift since their regular fellow had gone missing. In my eagerness to idly chat, I stayed just a bit too long, making it necessary for me to pick up the pace on the way back.
When I got back to work, I had a text from a friend. He'd been behind me on the street, full-throttle in his Acura, trying to keep up with me, but the ZX-14R had floated effortlessly away. I hadn't been trying to really hustle but I do recall seeing triple digits for most of the return trip although I have fifty miles of left of the break-in period. Even short-shifting at 6000rpm, the big green Kwacker is too fast for a street car at maximum attack. I could not be happier with this stout-hearted steed of a motorcycle, even if it kills me tomorrow morning.
What's the future of phrases like "busman's holiday?" They were the memes of their age, swelling in strength with every in-print repetition, adding judicious amounts of flavor to our discourse like carefully metered spices. Today's educated youngsters are, of course, absolutely obsessed with spice and flavor in their food --- but they have very little patience with, or time for, nuanced gradations of meaning within the written word.
Yet the idea of the busman's holiday will long outlast the term itself. We are all permanently leashed to our jobs now, whether through a BlackBerry or some deplorable "bring your own device" scheme at work. Even fast-food fry cooks are expected to be reachable via phone or text. The notion that a man was his own master when he drove out of the company parking lot in the evening has long since been rendered laughable. Take note, fellow busmen; the holiday's over.