Context of the story aside, my worst experiences with taxis have all been in Las Vegas. Being being asshats with lawyer ties to politicians, they are angry at their customers just for being customers. It has gotten to the point where I'd rather pay for a private car or take a hotel shuttle over a taxi any time we visit Las Vegas. I've been yelled at, my wife's bags tossed to the ground and just made really uncomfortable when dealing with them.
I've been to Vegas 50+ times, so I've probably taken 200+ taxi rides there. The most obnoxious behavior by a driver that I've ever seen or even heard of is talking loudly on the phone the entire ride. Not all of them are friendly, but I don't need them to be. No one has ever tried to "take me for a ride", probably because the strip hotels are in sight of the airport. And if you want a tip so that it ensures they won't take you on a long route when being picked up at the airport, say "take Tropicana" if you're going to the south side of the strip, or "take Swenson" if you're going to the north side. It tells them you've been there before and know how to get around. It's hardly the worst place to catch a cab. For that, I'd have to nominate New York City, which fits the description of one of the above posters who complained about very little English, no idea of how to get places in the quickest way possible, and most of all body odor. I can remember at least a dozen rides where the stench of the driver was overwhelming. If you really want to make cab rides better, require the drivers to shower before every shift.