My perception is that there is a small proportion of taxi drivers who choose to target tourists (and drunk expats late at night). These are obviously easier targets to scam. I guess every major tourist centre in the world has a subset of drivers who do this.
As a long term (big, whit, English-speaking) resident/immigrant who generally takes taxis to/.from places which are obviously not tourist places I have to say that my perception is that in the last couple of years the effect of Uber has been to improve the attitude of the taxi drivers I get. My only qualm is that many of the drivers (and their cabs) are very old and the standard of their driving is sometimes a bit iffy/worrying. No-one has tried to scam me or take me on a roundabout route for many years.
But I have to ask the tourists from the UK, for example, what sort of attitude you would expect from a black cab driver if you tried to converse with him or her entirely in Cantonese?