Meyers-Briggs is not a respected test of personality in psychometrics circles; it was invented based on an amateur's reading of Jung's theories of personality.
I've heard this plenty of times, and I know this anecdotal, but it does predict things. Every developer at FreshBooks when I was there was the same type. Every one of my girlfriends (that I got to take the test long after we broke up) is the same type.
There are correlations with IQ, with employment, with other accepted tests. The primary weakness of MB is that results are normally distributed across each letter, so a majority of the population is not strongly correlated with each letter. Just look at the hacker news response. I know it is self reported, but I don't buy that the two of the least populous types self reported themselves by a factor of 1000.
Insofar as people say a pop personality test describes them, it's likely due to the Forer Effect (http://en.wikipedia.org/wiki/Forer_effect).